Acquisition. Systems Support for , the Viking 19-75 Mission to Mars,- by jxc15528

VIEWS: 36 PAGES: 73

									                           .

      '       Telecommu,nications ,and Data             -    .   \   I       .'



. .           Acquisition. Systems Support for                                    ,       .   '   \   '   ,




              the Viking 19-75 Mission to Mars,-
              TheVikingLanderMonitor-Mission.                            '


                   1,983
                    March
              May 1980 to                                                             I

                                                            ~\




                                                    I
              D. J. Mudgway
                         ,-




              us
              r nn
              National Aeronautics and
                                               ,

              Space Administration
              Jet Propulsion Laboratory    '


          ,   California Institute of Techno,logy
              Pasadena] California
              -.
                               '   L.
   Telecommunications and Data
 Acquisition .Systems Supportfor
the Viking 1975 Mission to Mars
A recent panorama taken by the cameras of Viking Lander 1 on the surface of
Mars. The picture is a mosaic of six images taken on separate occasions over
the period June through August 1982.
JPL PUBLICATION 82-107




Telecommunications and Data
Acquisition Systems Support for
the Viking 1975 Mission to Mars
The Viking Lander Monitor Mission
May 1980 to March 1983

 .
D J. Mudgway




 May 15, 1983




 National Aeronautics and
 Space Administration
 Jet Propulsion Laboratory
 California Institute of Technology
 Pasadena, California
The research described in this publication was carried out by the Jet Propulsion
Laboratory, California Institute of Technology, under contract with the National
Aeronautics and Space Administration.
                                                                  PREFACE


         I n l a t e 1976 t h e r e w e r e t w o V i k i n g L a n d e r s a n d t w o V i k i n g O r b i t e r s                      ul
                                                                                                                                      in fl
o p e r a t i o no nt h es u r f a c ea n d            i n o r b i ta r o u n dt h ep l a n e tM a r s .            O f t h e s ef o u r
s p a c e c r a f t ,o n l yt h eV i k i n gL a n d e r         1 was a c t i v e i n t o O c t o b e r o f           1982. As t h e
Thomas A. M u t c h M e m o r i a l S t a t i o n , t h i s s p a c e c r a f t r e p r e s e n t e d t h e U n i t e d S t a t e s '
presenceonMars.                      As t h eV i k i n gL a n d e rM o n i t o rM i s s i o n         (VLMM), i gatheredand
                                                                                                                      t
regularly transmitted to Earth imaging                                   and meteorology data relative to its local
Martianenvironment.

         Thisreportcontinuesthedescriptionofthetracking             anddataacquisition
support for the Viking Mission to Mars published   i n f i v e p r e v i o u s volumes,which
a r e l i s t e d i n t h er e f e r e n c e s .

          The f i r s t v o l u m ed e s c r i b e so r g a n i z a t i o n ,p l a n n i n g ,i m p l e m e n t a t i o n ,a n dt e s t
a c t i v i t y f r o m i n c e p t i o n o f t h e P r o j e c t i n 1969 t o l a u n c h o p e r a t i o n s                 i n 1975.
Cruiseactivityfromthelaunch                                o f twospacecrafttothelandingofViking                                          1in
July 1976 i s d e s c r i b e d i n Volume 1 . The t h i r d v o l u m ec o v e r st h el a n d i n go ft h e
                                                                1
secondVikingLanderandMarsplanetaryoperationsfortwoOrbitersandtwo
L a n d e r st h r o u g ht h ee n do ft h ep r i m em i s s i o n                i n November 1976. V i k i n gE x t e n d e d
Missionsupportactivityfrom                             November 1976 t h r o u g h May 1978 i s d e s c r i b e d i n
Volume I V .           FromJune1978through                       A p r i l 1980, V i k i n gM i s s i o nO p e r a t i o n sw e r e
c o n d u c t e du n d e rv a r i o u s     names r e l a t e d t o t h e c o n d i t i o n o f t h e r e m a i n i n g                space-
c r a f t a n dt h ef u n d i n ga v a i l a b l et os u p p o r tm i s s i o no p e r a t i o n s .T h i sp e r i o d                     i s
d e s c r i b e d i n JPL P u b l i c a t i o n 82-18.

         The Deep Space Networkcontinued                               t o supportVikingfrom              May 1980 t o t h e p r e s -
e n t( M a r c h1 9 8 3 ) .T h i sp h a s eo ft h ec o n t i n u i n g             lifeoftheVikingProject                            was
termed,theVikingLanderMonitorMission,and                                         was e x p e c t e d t o c o n t i n u e t h r o u g h t h e
y e a r1 9 9 4 .H o w e v e r ,t h es p a c e c r a f tf a i l e d           i n November 1982,       and          i n March     1983,
t h e m i s s i o n was c o n s i d e r e d t o h a v e ended.

         I n t h i s document, t h e t r a c k i n g a n d d a t a a c q u i s i t i o n s u p p o r t f o r t h e V i k i n g
LanderMonitorMissionfrom                                May 1980 t o March1983 i s d e s c r i b e d t o g e t h e r w i t h a n
o v e r v i e wo f: ' t h es c i e n c er e s u l t s .       The e v e n t s l e a d i n g t o t h e f a i l u r e and t h eN e t -
work'seffortstorecovertheLandersignalarealsoincluded.



                                                                      /                   &&
                                                                        N. A. R e n z e t t i
                                                                                                                    0




                                                                       V
                                                                ABSTRACT


     From May 1980 u n t i l t h e V i k i n g L a n d e r S p a c e c r a f t f a i l e d t o t r a n s m i t a down-
link t o E a r t h
               i n November 1982, t h e Deep Space N e t w o r kp r o v i d e dt r a c k i n ga n dd a t a
acquisition support to the Viking Lander Monitor Mission                                   (VLMM).

          T h i sr e p o r tg i v e st h eb a c k g r o u n df o rt h e              VLMM a n d d i s c u s s e s t h e t e c h n i c a l   and
o p e r a t i o n a l a s p e c t s o f t h e t r a c k i n g and d a t a a c q u i s i t i o n s u p p o r t t h a t t h e N e t w o r k
was c a l l e du p o nt op r o v i d e .                 An o v e r v i e wo ft h es c i e n c er e s u l t so b t a i n e df r o mt h e
i m a g i n g ,m e t e o r o l o g i c a l ,a n dr a d i os c i e n c ed a t a           isalsogiven.

      The r e p o r t c o n c l u d e s w i t h a d e s c r i p t i o n o f t h e i n t e n s i v e e f f o r t s t h a t were
made t o r e c o v e r t h e m i s s i o n f r o m November 1982 u n t i l t h e e f f o r t was d i s c o n t i n u e d
i n March 1983.




                                                                       v i
                                                CONTENTS


I   .           INTRODUCTION    ............................                                1-1


I
1       .       BACKGROUND    .............................                                 2-1


 1
I 1         .   DSNSUPPORT       ............................                               3-1

                A   .   OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . .      3-1

                B.      CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . .      3-5

                C.      REAL-TIME L I N K TO
                                          THE    UNIVERSITY OF
                                                            WASHINGTON    ........          3-5

                D.              S-BAND
                        AUTOMATIC DOWNLINK           ...................                    3-10

                E   .         L1
                        THE V - RECOVERY  EFFORT     ...................                    3-12


IV      .       VLMM SCIENCE RETURN       ........................                          4-1

                A   .   RADIOSCIENCE     .........................                          4-1

                B   .   METEOROLOGY   ..........................                            4-2

                C   .   IMAGING EXPERIMENT    ......................                        4-6


V   .             .............................
                CONCLUSION                                                                  5-1

DEFINITION OF ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . .                 6-1

ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                  7-1

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                  8-1

APPENDIXES

                A.          NEWS
                        SAMPLE RELEASE        ......................                        A-1

                B.      VIKING LANDER MISSION SUPPORT EXTENSION REQUEST  ........           B-1

                C   .   VIKING LANDER
                                    MONITOR   MISSION
                                                    DIRECT-LINK    REQUEST SUMMARY . . .    C-1

                D.                  MONITOR
                        VIKING LANDER         MISSION
                                                    DIRECT-LINK    REQUEST DETAIL   . . .   D-1

                E.      AN EXAMPLE OF VIKING LANDER
                                                  SEQUENCE
                                                         OF
                                                          EVENTS          ........          E-1

                F.             STRATEGY
                        RECOVERY          L O G FOR VIKING LANDER 1 . . . . . . . . . . .   F-1

                G.      ANNOTATED BIBLIOGRAPHY    ....................                      G-1

                H.      VIKING FACTS . . . . . . . . . . . . . . . . . . . . . . . . .      H-1

                                                    v ii
Figures

          2.1   . V i k i n gL a n d e r . . . . . . . . . . . . . . . . . . . . . . . . .                     2-3

          22
           .    . V i k i n gL a n d e r 1 Radio System. F u n c t i o n a lB l o c kD i a g r a m . . . .     2-5

          3.1   . T y p i c a lL a n d e r Pass . . . . . . . . . . . . . . . . . . . . . .                    3-2

          32
           .    . V i k i n gL a n d e rU p l i n kA c q u i s i t i o n Sequence . . . . . . . . . . .        3-4

          3.
           3    . P r e d i c t e dD o w n l i n kS i g n a lL e v e l From Vikins Lander 1 . . . . .          3-4

         3.
          4     . V i k i n gL a n d e rT e l e m e t r yC o n f i g u r a t i o n . 1 4 . . . . . . . .
                                                                                     DSS                       3-6

         3.
          5     . V i k i n gL a n d e rT r a c k i n gC o n f i g u r a t i o n . 1 4 . . . . . . . . .
                                                                                    DSS                        3-7

         3.
          6     . V i k i n gL a n d e r Command C o n f i g u r a t i o n . 1 4 . . . . . . . . .
                                                                                   DSS                         3-8

         .
         3
         7      . Viking Lander Monitor and Operations Control Configuration                         .
                    DSS14         ............................                                                 3-9

         3
         .
         8      . R e a l - T i m eD a t aT r a n s f e rt oU n i v e r s i t yo fW a s h i n g t o n ......   3-11

         4.1    . T y p i c a lV i k i n gL a n d e r 1 PressureRecord . . . . . . . . . . . .                 4-3

         42
          .     . T y p i c a lV i k i n gL a n d e r 1 LocalAmbientTemperatureRecord                    ...   4-4

         43
          .     . Y i k i n g L a n d e r s 1 and 2 L o c a l AmbientPressure f o r 3 M a r t i a n
                  Years . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                              4-5

         44
          .     . V i k i n gL a n d e r 1 ComparativeMarsImages . . . . . . . . . . . .                       4-7

         4.
          5     . V i k i n gL a n d e r 1 Seven-Picture Sequence . . . . . . . . . . . .                      4-7

Tables

         2.1    . V i k i n gO r b i t e r      1 SurveyMission.                  .............
                                                                               1980                            2-2

         2.
          2     .   G e n e r a lV i k i n gO r b i t e rS t a t i s t i c s    ...............                2-3

         2
         3
         .      . V i k i n gL a n d e r 1 SpacecraftTelecommunicationParameters . . . .                       2-6

         3.1    . Comparative Success Rates f o r V i k i n gL a n d e rD a t aA c q u i s i t i o n . .       3-2




                                                                      vi
                                                                       i
                                                                       i
                                                                .
                                                               I INTRODUCTION


                   I n l a t e 1976 t h e r e w e r e t w o V i k i n g L a n d e r s a n d t w o V i k i n g O r b i t e r s                    u
                                                                                                                                            i n fll
    o p e r a t i o no na n da r o u n dt h ep l a n e tM a r s .                O f t h e s ef o u rs p a c e c r a f t ,V i k i n gL a n d e r     1
    h a dt h el o n g e s tl i f e ;         t was s t i l l a c t i v e i n October
                                              i                                                   1982.           As t h e Thomas A. Mutch
    M e m o r i a lS t a t i o n ,V i k i n gL a n d e r        1 r e p r e s e n t e dt h eU n i t e dS t a t e s 'p r e s e n c e         on Mars.
    As t h e V i k i n g L a n d e r M o n i t o r M i s s i o n        (VLMM), i s c o n t i n u e d t o ' g a t h e r a n d r e g u l a r l y
    transmit to Earth imaging and meteorology data relative to its local Martian
    environment.         However,              l a t e i n 1982, t h e l a n d e r f a i l e d t o r e s p o n d t o                uplink com-
    mands f o r a d o w n l i n kt r a n s m i s s i o n .R e p e a t e da t t e m p t so v e r                 a p e r i o do ff o u r
    months f a i l e d t o r e c o v e r t h e l a n d e r s i g n a l . F i n a l l y ,               i n M a r c h1 9 8 3 ,t h eV i k i n g
I
    Lander M o n i t o r M i s s i o n was t e r m i n a t e d .

                 P r e v i o u s t r a c k i n g and d a t a s y s t e m s s u p p o r t f o r t h e V i k i n g M i s s i o n t o M a r s
    a r e d e s c r i b e d i n Refs. 1-1 t h r o u g h 1-5.




                                                                             1-1
                                                          1 .
                                                           1       BACKGROUND


              I n July 1980, a p r e s sr e l e a s e( A p p e n d i x              A) announced t h ei m m i n e n tc o n c l u s i o n
o ft h eV i k i n gO r b i t e r    1 (VO-1) M i s s i o n and t h eb e g i n n i n go ft h e                        VLMM.        T h i s an-
nouncementmarkedtheend                     o f themajorVikingoperationsactivity,                                           and t h e b e g i n -
n i n g o f a new e r a o f l o w - l e v e l s u p p o r t         o f anautomaticlandermissiononan                                      "op-
p o r t u n i t y "b a s i s .   The r e q u e s tf o rt e l e c o m m u n i c a t i o n sa n dd a t aa c q u i s i t i o ns u p p o r t
f r o m t h e Deep Space Network (DSN) f o r t h e VLMM through1990 i s reproduced i n
Appendix B.

              A c o m p r e h e n s i v ea n di n f o r m a t i v ea c c o u n to ft h el a s ty e a ro ft h eV i k i n gM i s -
s i o n i s g i v e n i n Reference 2 - 1 f r o m t h e p o i n t o f v i e w o f                      one o f t h e s c i e n t i s t s
most c l o s e l y i n v o l v e d with t h e p r o j e c t f r o m i t s i n c e p t i o n              i n 1969.     Table       2-1 i s
t a k e nf r o mR e f e r e n c e     2 - 1 t o show t h e p r i n c i p a l m i s s i o n e v e n t s o f t h e f i n a l           months
of Viking Orbiter                 1.

              O n August 7 , 1980, a t 2015 GMT, t h e Deep Space S t a t i o n (DSS) 6 1 i n Spain
s e n t a command t o VO-1 t o turn o f f i t s S- and X-band t r a n s m i t t e r s .                                       To s a t i s f y
i n t e r n a t i o n a l a g r e e m e n t sr e g a r d i n gu n c o n t r o l l e dr a d i ot r a n s m i s s i o n sf r o mm a c e -
craft,the            s- and X-band t r a n s m i t t e r s w e r e t u r n e d o f f b e f o r e g r o u n d c o n t r o l                was
lost.         Subsequent RF searches a t t h e VO-1 f r e q u e n c i e sv e r i f i e dt h a tb o t ht r a n s -
m i t t e r sr e m a i n e do f f .      These searches           were   repeated       several    times  over    subsequent
weeks, but no c a r r i e r s w e r e d e t e c t e d .

            Thus ended t h e V i k i n g O r b i t e r             1 M i s s i o n t o Mars a f t e r f i v e y e a r s o f c o n t i n u -
ous o p e r a t i o n a ls u p p o r tb yt h eN e t w o r k .T h r o u g h o u tt h i sp e r i o d ,t h eN e t w o r kp r o -
v i d e dc o n t i n u o u sm i s s i o ns u p p o r ta n d         was e f f e c t i v e i n d e v e l o p i n g o p e r a t i o n a l
t e c h n i q u e st o o v e r c o m ep r o b l e m sc a u s e db yh i g h l yr e d u c e ds t a f f i n gl e v e l s ,o b s o l e t e
h a r d w a r ea n ds o f t w a r e ,a n dt h es t e a d ya t t r i t i o no fe x p e r i e n c e dV i k i n g . o p e r a t i o n s
staff.

            The V i k i n g P r o j e c t S c i e n t i s t c o m p i l e d t h e s t a t i s t i c s o f g e n e r a l i n t e r e s t
g i v e n i n T a b l e 2-2 r e g a r d i n g t h e t w o V i k i n g O r b i t e r s a n d t h e                Deep Space Network
support.

              V i k i n gL a n d e r 1 ( F i g u r e 2-1) i s l o c a t e d i n C h r y s eP l a n e t i aa t                            48"
                                                                                                                                  22"N, and
was i n a n a u t o m a t i c o p e r a t i o n a l         mode s i n c e M a r c h 1 9 7 9 , t r a n s m i t t i n g s t o r e d i m a g i n g
a n dm e t e o r o l o g yd a t ao na c t i v a t i o nf r o m          one o f t h e deep           space          s t a t i o n s .T h i s
a c t i v i t y became i d e n t i f i e d a s t h e V i k i n g L a n d e r M o n i t o r M i s s i o n                (VLHM) on Novem-
b e r 6,1979,andcontinued                        t op r o v i d er e g u l a rt r a n s m i s s i o n so fs t o r e de n g i n e e r i n g ,
imaging,andmeteorologicaldatathroughOctober1982.

              The V i k i n gL a n d e r 1 (VL-1) s p a c e c r a f tr a d i os y s t e mh a d                    one a c t i v e r e c e i v e r
( o ft w o )a n dt w oa c t i v et r a n s m i t t e r s .                 A s t o r e dp r o g r a m i n t h el a n d e rt u r n e d       a
transmitteronat                      a s p e c i f i e dt i m ec o r r e s p o n d i n g     t o e a c hE a r t hv i e wp e r i o d ,     and
a l o n g - t e r ms t o r e dp r o g r a mm a i n t a i n e dt h ea n t e n n a ' sE a r t h - p o i n t i n gd i r e c t i o n .            The
E a r t h - p o i n t i n ga n t e n n ap r o g r a m        was w r i t t e n t o b e v a l i d t h r o u g h       1994.         In the
periodbetweenNetworkcommunicationpasses,imagingandmeteorologicaldatawere
a c c u m u l a t e do nt h et a p er e c o r d e r sf o rr e a d o u td u r i n ge a c hN e t w o r kp a s s .




                                                                      2- 1
               Table 2 - 1 .      V i k i n gO r b i t e r      .
                                                               1 SurveyMission,                 1980

      Date                                                                             Event

A p r i l 23               O r b i t t r i mb eo un v eiy s i o n
                                               g
                                              tsi rm s

May 1 7                    L a s t Sun o c c u l t a t i o n

June 1 5                  L ia s t a r o b s e r v a t i o n
                             nfr ‘ ed                                     o f pha n e t
                                                                              tle

July 12                 E La l
                          c th
                       o ca ru stta t i o n

July 1 4                      n
                           Fiim a lg i n g                 s rf
                                                    sequenceu ov e y

July 1 5                                       n
                           F i r s t engine burn i p r o p u l s i o n t t e s t
                                                                 sys em

July 1 7                   Second engine burn i n p r o p u l s i o n t t e s t
                                                                sys em

July 1 8                                                 n
                          T h i r d e n g i n e burn i p r o p u l s i o n s y s t e m t e s t f a i l s t o
                          e x h a u s t p r o p e l l a n t as i n t e n d e d

     y 26
J u lTwo                      imaging sequences:        s u r lva y
                                                                 om
                                                   g l o b a f rep o a p s i s ,
                          andground-track  strip near periapsis

July 28                                p e ap
                                       n i
                          Ground-track s t r r ira p s i s

July 30                       n a
                          F i ma lg i n g                     gr e:          naeai
                                                    s e q u e n co u n d - t rpecrkra p s i s

July 3 1                  Fourthengineburn               i n propulsionsystemtestexhausts
                          p r o p e l l a n t , Rev. 1 4 8 5

August 5                  Playback o f l a s tb i tp i r t u r e ,
                                          or        ec                                   Rev. 1 4 8 8

August 7 -                O r b i t e r power t u r n e dfo u n d
                                                      o fy
                                                       br
                                                       g                                   command, Rev. 1 4 8 9




                                                     2-2
                                     T a b l e 2-2.        G e n e r a lV i k i n gO r b i t e rS t a t i s t i c s

                                        Parameter                                                        vo-1                      vo- 2
                         rom end
          Number o f d afy sa u ntc h
                           l      o                                   o f mission                      104
                                                                                                   1813.98 9.52

          Number f o f o r b i t s
               o                           Mars                                         706.1 1488.0

          Number o f p i r e u r e s e d
                         ct cord                           in orbit                                36 622
                                                                                                  1 6 ,,0 4 1

          Number o f d a t a b i t s p l a y e d b a c k f r o m t h e t w o
                                                                                                             9                               9
                r
          t a p ee c o r d e r ( i n c l u d i n ga n d erre l a d a t a )
                               s                 l               y                                 357.7 x 10                  1 6 1 . 3 x 10

                  r or d
               atcca ae s ,
          Tape r ehrevsdle r
                       s                                                km                      2955
                                                                                             1397

          Number o f commands s e n t by ttw o r k
                                      Ne he                                                                            269,500

          Number o f t r a c k ip a s ss u p p o r t e d
                                ng es                                     by tN e t w o r k
                                                                              h                                          7,380

          Amount orfa c k i n gm e o v i d e d
                 t           ti pr                                  by the
                                                                        Network,                   h                    56,500




                                                                      n               S-BAND HIGH GAIN ANTENNA (DIRECT)




                                          MAGNIFYING MIRROR

                                           RADAR ALTIMETER
                                                                   i".. 1
                                           ELECTRONICS 2




                                                                                                                               METEOROLOGY
SENSORS              UHF ANTENNA (RELAY)

                                                                                                                          METEOROLOGY
                                                                                                                          BOOM ASSEMBLY
                   (INSIDE COVER)

               RTG WIND COVER (2 EA)                                                                                   LANDING SHOCK ABSORBER

                                                                                                                              ET CLEANING


                 ROLL ENGINE (4 E                                                                                              LEG 2

               TERMINAL DESCENT
               PROPELLANT TANK (2 EA)

            RADAR ALTIMETER ANTENNA AND
            TERMINAL DESCENT LANDING RADAR
            (UNDERSIDE OF LANDERSTRUCTURE)
                                                                                                                      SURFACESAMPLER BOOM

                                                                   TERMINAL DESCENT
                                                                   ENGINE (3 EA)                                           COLLECTORHEAD
                                                                   18 NOZZLECONFIGURATION              MAGNETS




                                                      F i g u r e 2-1.         Viking Lander


                                                                            2- 3
           A functionalblockdiagramofthe                      V L - 1 r a d i o s y s t e m i s shown i n F i g . 2-2.
Receiver 1 on t h a t d i a g r a m f a i l e d p r i o r t o t h e          end o f VLMM, a l t h o u g h i t s associ-
a t e d command d e t e c t o r and m o d u l a t o r - e x c i t e r c o n t i n u e d t o      w o r k s a t i s f a c t o r i l y , as
d i d a l l o t h e r elements o f t h er a d i o system.           Loss           o f r e c e i v e r 1 f o r c e da c c e s st o
e i t h e r command d e c o d e rt h r o u g hr e c e i v e r   2, which i s permanentlyconnectedtothe
h i g h - g a i na n t e n n a . Thus, b o t h u p l i n k and downlink           communication               w i t h t h e space-
c r a f t was dependentupon t h e h i g h - g a i n a n t e n n a a u t o m a t i c p o i n t i n g p r o g r a m .

         S p a c e c r a f tt e l e c o m m u n i c a t i o nc h a r a c t e r i s t i c sa r eg i v e n        i n Table 2-3.

         By Januaryof             1982, t h r e e o f t h e f o u r             8-A.h, n i c k e l - c a d m i u m b a t t e r i e s         on-
b o a r dV i k i n gL a n d e r    1 showed s i g n s o f s i g n i f i c a n t                l o s s o fe n e r g y - s t o r a g ec a p a c i t y .
An i n t e n s i v e p r o g r a m o f d e e p - d i s c h a r g e b a t t e r y c o n d i t i o n i n g       was begun i n January
1982 i n a n a t t e m p t t o r e t u r n t h e b a t t e r i e s t o l e v e l s                   o f c a p a c i t ya p p r o a c h i n ge a r l y
missionlevels.

         The r e c o n d i t i o n i n g was r e l a t i v e l y s u c c e s s f u l , b u t t h e a b i l i t y o f t h e b a t t e r -
i e st or e t a i nt h e i re n e r g y - s t o r a g ec a p a c i t y     was poor.            I n one case, 80% o f t h e
g a i n e d c a p a c i t y was a g a i n l o s t o n l y f o u r months a f t e r t h e l a s t r e c o n d i t i o n i n g
cycle.

          In an attempt to extend the life of the batteries                                           as l o n g as p o s s i b l e , t h e
b a t t e r y . p e r f o r m a n c e and t h e method o f r e c o n d i t i o n i n g t h e b a t t e r i e s            was reviewed
i n d e t a i lb ys e v e r a le x p e r t s         i n t h i sf i e l d .T h i sr e v i e w ,h e l d             i n August 1982,
ledtotheadoptionof                        a new b a t t e r y c o n d i t i o n i n g and o p e r a t i n g s t r a t e g y .          Reauc-
t i o n i n t h ef r e q u e n c yo fb a t t e r yc h a r g i n g ,d e e p e rd i s c h a r g i n gd u r i n gr e c o n d i t i o n -
i n g , and s h o r t e r d u r a t i o n o f r e c h a r g i n g w e r e c o n s i d e r e d k e y i t e m s           in prolonging
t h eV i k i n gL a n d e rb a t t e r yl i f e .           These s t r a t e g i e sw e r ei n c o r p o r a t e d          i n t h eV i k i n g
Lander sequences,and                    t h e e f f e c t s o n b a t t e r yp e r f o r m a n c ew e r ec a r e f u l l yo b s e r v e d .

          F o l l o w i n g one o f t h e u p l i n k sequences,however,                    t h e n e t w o r k was u n a b l e
t o d e t e c tt h ep r e s e n c eo f     a d o w n l i n ks i g n a l .           Subsequent e f f o r t s t o command t h e
downlink "on," r e c h a r g e t h e b a t t e r i e s ,            and p o i n tt h el a n d e ra n t e n n aw e r eu n s u c -
c e s s f u l i n p r o d u c i n g a d o w n l i n kt r a n s m i s s i o n .A f t e r     f o u r months o f unsuccessful
recovery efforts, the                  VLMM was t e r m i n a t e d i n March 1983.




                                                                        2-4
    ccu-      --- - - --
    r                     r
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4
    I       COMMAND
             DECODER
                                                                             MOD-
                                                                            EXCITER
                                                                                                                      LGA
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    I         NO. 1                NO. 1                                     NO. 1

    I
    I
                                                                                                                       TWTA
                                                                                                                       NO. 1
                                                                                                                               -
    I                        b       TRS         I                                          I,
                                                                                                  4-PORT
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*-
4                                                                                                 HYBRID
    I                                            I   TRANSPONDER NO. 2
                                                                                            I                          TWTA

    I                                                                             - 1I                         1       NO. 2



-
                                                                             ”




            COMMAND      COMMAND                                             MOD-
        1    DECODER .C- DETECTOR                                           EXCITER
    I         NO. 2       NO. 2                                              NO. 2
    I
    I
                                                                                            1 -
                                                                                                     .         I
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            SINE   COSINE         TO                                                                HGA
                                  HGA D lRM                                                         PORT
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                      F i g u r e 2-2.     V i k i n g Lander 1 Radio System, F u n c t i o n a l B l o c k Diagram
            T a b l e 2-3.          V i k i n gL a n d e r        1 S p a c e c r a f tT e l e c o m m u n i c a t i o nP a r a m e t e r s
I




I
                              Parameter                                                                         Value

            T r a n s m i tf r e q u e n c y ,        MHz                                 2294.629630       13a)
                                                                                                     (channel

            Tr wer,
            p oa n s m i t t e r                      dBm                                 42.6

I            High-gain
            antenna,                                  dB                                  22.3,      t r a n s m i t ; 21.3,        receive

            Low-gainantenna,                     dB                                       4.5,     r e c e i v eo n l y

            R e c e i v e rn o i s ef i g u r e ,           dB                            7.8

             System n o i s e t e m p e r a t u r e ,             K                       1549, h i g h g a i n ;         1150, l o w g a i n

             Receivefrequency,                        MHz                                 2112.971451       13b>
                                                                                                     (channel

             Science b i t r a t e , b i t s l s                                          1000, 500, and
                                                                                                       250
    ,
             Coding                                                                       B i o r t h o g o n a lb l o c kc o d i n g( 3 2 : 6 )

             Engineering b i t r a t e , b i t s l s                                      8-113,       uncoded

             S u b c a r r i e rf r e q u e n c y ,         kHz                             ,
                                                                                          12engineering;                  72, s c i e n c e

             Command b i t r a t e , b i t s / s                                          4




        I




                                                                               2-6
                                                              1.
                                                             11        DSN SUPPORT


         The h i s t o r y o f t r a c k i n g and data a c q u i s i t i o n s u p p o r t f o r t h e V i k i n g P r o j e c t
    from i t s i n c e p t i o n t h r o u g h mid-1980 i s g i v e n i n R e f s . 1-1 t h r o u g h . 1 - 5 .


    A.
0PERAT:IONS

             A c o m p t e h e n s i v er e p o r to n        a l l t h e d i r e c t DSN t o VL-1 d o w n l i p k o p p o r t u n i t i e s
    from the beginning of the Viking Lander Monitor Mission                                            i n August1980 t o O c t o b e r
    1982 i s g i v e n i n Appendixes C and D.                             Over t h i s 2-yr p e r i o d , t h e s u c c e s s r a t e f o r
    t h ee n t i r eN e t w o r k      was 90% f o r t e l e m e t r y (TLM) and 80% f o r r a d i o m e t r i c ( T r a c k i n g
    System (TRK)) d a t a .S u c c e s sr a t e                     istheratioof             good   passes      t o t o t a l passes
    s c h e d u l e df o rt h eN e t w o r k .P a s s e sa r ej u d g e d               "good" o r "no    good"        o nt h eb a s i so f
    t h e amount and q u a l i t y o f t h e d a t a r e t u r n .                    A comparison o f t h e d a t a a c q u i s i t i o n
    successratefor1980,1981,and1982                                        i s g i v e n i n T a b l e 3-1.     Success r a t e s f o r
    allstationsoverthe3-yrperiodare                                        i n theregionof            80% t o 90%. A summary
    of the direct-link requests is given                                 i n Appendix C, w i t h t h e d e t a i l s o f e a c h p a s s
    g i v e n i n Appendix D.                 These d a t a a f f o r d a good i n s i g h t i n t o t h e o v e r a l l p e r f o r -
    mance o f t h e N e t w o r k i n s u p p o r t i n g t h e s e r a t h e r            random V i k i n g L a n d e r p a s s e s o v e r
    an e n t i r e 3 - y r p e r i o d .
                                                         I




             The VLMM d i d n o t e n j o y a h i g h p r i o r i t y i n t h e a s s i g n m e n t s o f t r a c k i n g t i m e .
    Frequently an available view period                      was l o s t becauseantennatime                     was n o t a v a i l -
    a b l e , o r a p a s ss c h e d u l e df o rV i k i n g  was preempted f o r a n o t h e r f l i g h t p r o j e c t .
    Examples o f t h i s a r e g i v e n         i n Appendix D.

              The VLMM c r e a t e d some o p e r a t i o n a l d i f f i c u l t i e s f o r t h e N e t w o r k o p e r a t i o n s
    teams.          D u r i n gt h eV i k i n gp r i m em i s s i o n ,          command sequepces         developed by t h e f l i g h t
    teams w e r e l o a d e d i n t o I B M              360-75 c o m p u t e r s l o c a t e d i n t h e JPL M i s s i o n C o n t r o l
    Center.Fromthere,                          allinteractionswiththe                    Deep Space S t a t i o n Command System -
    i n c l u d i n gv e r i f i c a t i o n ,t r a n s m i s s i o n ,   and c o n f i r m a t i o n - wereautomatic.                    With
    thedecommissioning o f t h e s e t h r e e c o m p u t e r s a t t h e e n d o f t h e p r i m e m i s s i o n , t h e
    Networkacceptedresponsibilityforsendingall                                              VL-1 commands m a n u a l l y , a l t h o u g h
    t h e s m a l l VLMM o p e r a t i o n s s t a f f r e m a i n i n g w i t h t h e p r o j e c t a c t u a l l y d e s i g n e d t h e
    d e s i r e d command sequences.                        The command sequence d e s i r e df o rt h ep a s s                    was t r a n s -
    m i t t e d by t h e N e t w o r k O p e r a t i o n s P r o j e c t E n g i n e e r       (NOPE) t o t h e s t a t i o n by t e l e t y p e
     (TWX).         A n example o f a VikingLandersequence                               o f e v e n t s i s g i v e n i n Appendix E.
    A t t h e DSS, t h e T X command sequence was l o a b e d m a n u a l l y i n t o t h e
                                      W                                                                                     command b u f f e r ,
    r e c a l l e d by t h e NOPE, and v e r i f i e d f o r a c c u r a c y .

             A t y p i c a ll a n d e rp a s si si l l u s t r a t e d            i n F i g . 3-1.         D u r i n gt h ef i r s t      60 m i n
    o ft h ep r e t r a c kp r e p a r a t i o n         (PTP), t h e s t a t i o n c o u n t e d        down t h e t e l e m e t r y ,     command,
    m o n i t o r ,a n dr a d i om e t r i cd a t as y s t e m s .D u r i n gt h el a s t                    30 m i n o f t h e PTP, t h e
    stationturnedoverthe                         command s y s t e mt oN e t w o r kA n a l y s i s             Team   (NAT) command             for
    a command-system v a l i d a t i o n . A f t e r                  NAT  command         v a l i d a t e dt h e     command system, t h e
    DSS e n t e r e d t h e commands r e q u i r e d f o r t h e p a s s ; t h e s e                   commands w e r er e c e i v e d by T X          W
    message f r o mt h e NOPE i n t o t h e m a n u a lb u f f e r .                      NATcommand            t h e nr e c a l l e dt h em a n u a l
    b u f f e r a n dv a l i d a t e dt h e        command b i t p a t t e r n . F o l l o w i n g v e r i f i c a t i o n           by NAT com-
    mand, t h e DSS t h e n t r a n s f e r r e d t h e c o n t e n t s o f t h e m a n u a l b u f f e r t o M o d u l e                   1 of
    t h e DSS Command System.



                                                                         3-1
           T a b l e 371.   C,omparative      Rates
                                        Success                       f o rV i k i n gL a n d e rD a t aA c q u i s i t i o n

                                                                          Passes

Station   Year                                              Good                                     Bad     Rate,           Success                       %

                   TRK       TLM         TRK          TLM                                                                            TLM             TRJK

          1980           Goldstone                     2              2                     1           67    1                       67
                         Australia                     3              2                     0                 1                      100              67

                         Spain                         3              3                     0                 0                      100             100

          1981           Goldstone                     4              3                     1                    2                    80              60
                         Australia                     9              9                     2              82 2                       82

                         Spain         11             11                                    2              35 2                       85

          1982           Goldstone                     8              7                     1           78    2                       89
                         Australia                    13           10                       0                 3                      100              77
                         Spain                        12           11                       0                 1                      100              92

          1980           A l l stations                8              7                     1                 2                       89              73
          1981                      23
                         A l l stations               24                                    5              79 6                       83
          1982                    28
                         All stations                 33                                    1              82 6                       97




                                        COMMAND UPLINK


                                        SWEEP START                                         M        A TURN ON

                                                                                            DOWNLINK START                            DOWNLINK STOP
                                 PROGRAM START
           SWEEP
           ACQUISITION
                                                                                            DOWNLINK
           COMMANDAND        SPACECRAFT TIME
                                                                      I I   \                                        \
           SYSTEM                                                                                                        \
                                                                                                                         \
                  LOCK
           DETECTOR                                                                                                          \
                                                                                \
                                                                                    \                                            \
          COMMAND DATA VALIDATION
                                                                                        '\
                                                                                        \

                                                                                                                                     '\
                                                                                                                                 \\


                                                                                            \
                     DSS                                                                    \
                                                                                                \                                     \\     DSS POST
                                                                                                \,
                                                                                                 \                                        \\CALIBRATION
                                                                                                                                            \




                    a        90 rnin

                    a                                          2H) rnin MAXIMUM



                                         F i g u r e 3-1.    T y p i c a l Lander Pass




                                                               3- 2
             Followingthestartoftrack,approximately                     15 m i n w e r er e q u i r e df o rt h e
u p l i n k a c q u i s i t i o n sweep; t h e r e was a padof 1 2 m i n i n w h i c h t o turn on command
m o d u l a t i o nb e f o r et h e  command window    opened.  The command window was u s u a l l y o f
15 m i n duration.

             The a c t u a l d o w n l i n k l a s t e d    60 m i n when t h e s p a c e c r a f t was c o n f i g u r e d o n
TWTA1.        A l l o w i n g a 3 0 - m i n u t ep o s t c a l i b r a t i o no nt h er a n g i n gs y s t e m    and t h e maximum
one-way       lighttimeexpectedduringthemission,the                                              maximum VLMM t r a c k was 270 m i n .

              Because o f t h e t e m p e r a t u r e - s e n s i t i v e n a t u r e o f t h e o s c i l l a t o r s o n b o a r d t h e
V i k i n gL a n d e ra n dt h el a r g et e m p e r a t u r ee x c u r s i o no nt h ep l a n e t ' ss u r f a c e ,                      a non-
c o n v e n t i o n a l a c q u i s i t i o n sweep p r o c e d u r e was d e v i s e d t o i n s u r e r e l i a b l e                 two-way
t r a c k i n g .F i g u r e       3-2 i l l u s t r a t e st h i sp r o c e d u r e .

               Because t h e l a n d e r t r a n s m i t t e r       was programmed " o f f r ' a f t e r e a c h s u c c e s s f u l
d i r e c t - l i n k p a s s ,t h el a n d e ru p l i n k        was a l w a y sa c q u i r e d i n t h eb l i n d .U n l i k e
n o r m a l a c q u i s i t i o n sweeps, t h e i n i t i a l t r a n s m i t XA was a l w a y sa b o v et h a t                    shown on
t h ep r e d i c t s ,     a n dt h ef i r s t       ramp was always i n t h en e g a t i v ed i r e c t i o n .U n d e rn o r -
m a lc o n d i t i o n s ,t h es p a c e c r a f tr e c e i v e r       was c a p t u r e d d u r i n g t h i s p o r t i o n o f t h e
sweep.. The n e x t p o r t i o n o f t h e                  sweep was a t a s l o w e r r a t e a n d         in thepositive
d i r e c t i o no v e rt h e      same range.               The f i n a l downward    ramp      t o o kt h es p a c e c r a f tr e -
c e i v e r t o a n o m i n a lc e n t e rf r e q u e n c y ,w h i c h       was d e s i g n a t e d t h e t r a c k s y n t h e s i z e r
f r e q u e n c y (TSF) f o rt h ep a s s .

              T h i s p r o c e s s was time-consumingand                         cumbersome, and v e r y s u s c e p t i b l e t o - h u m a n
e r r o r ,p a r t i c u l a r l y      i f a l o n g command sequence was c a l l e d f o r .                               I i s a tributeto
                                                                                                                              t
t h e NetworkOperations                      Team t h a t m i s t a k e s s e l d o m o c c u r r e d ; t h i s f i n e r e c o r d h a s
b e e nr e c o g n i z e db yt h eP r o j e c t            Manager i n a memo o f commendation.                                    I n c o n t r a s tt o
command'ing, t h et e l e m e t r yo p e r a t i o n a lp r o c e d u r e s                   became much s i m p l e r .T h e r e                 was
n or e a l - t i m ep r o c e s s i n go ft e l e m e t r ye n g i n e e r i n go rs c i e n c ed a t aa t                           JPL.     Instead,
a real-timerecordofthetelemetrystream                                             was made by t h e d a t a r e c o r d s g e n e r a t o r
i n t h eN e t w o r kO p e r a t i o n sC o n t r o lC e n t e r               (NOCC).         From t h i s , and u s i n g r e c a l l s i f
n e c e s s a r y ,a nI n t e r m e d i a t eD a t aR e c o r d             (IDR) was     made          a n ds h i p p e di m m e d i a t e l yt o
t h eU n i v e r s i t yo fW a s h i n g t o nw h e r et h et e l e m e t r yp r o c e s s i n g                   was c a r r i e d o u t .          The
VLMM s p a c e c r a f t e n g i n e e r a c c e s s e d t h i s s o u r c e f o r s p a c e c r a f t e n g i n e e r i n g d a t a a n d
theimagingandmeteorologicalinvestigatorsalsoobtainedtheirdatafromthis
source.

              Signallevelsonthe                 up and down t e l e c o m m u n c a t i o n l i n k s b e t w e e n t h e    DSN
and V L - 1 were q u i t e h i g h a n d g e n e r a l l y a l l o w e d t h e       DSN t h e o p t i o n o f s u p p o r t i n g t h e
V L - 1 passeson             a 64-m o r 34-m antenna.             A plotofdownlinksignallevel                             andEarth-
Mars   range     through     1988          i s shown i n F i g . 3-3.         T y p i c a l S-band downlink           telecom-
m u n i c a t i o n sp a r a m e t e r s i n October1982were:

             D o w n l i n kr e c e i v e dc a r r i e rp o w e r ,   dBm                                          -148.2
                        DSS r e c e i v e rm a r g i n ,       dB                                                    26.9
                                 T e l e m e t r y SNR a t , 8-113 b i t s l s , dB                                  20.9
                                 T e l e m e t r y SNR a t 1000 b i t s / s , dB                                      6.1
             Uplinkreceivedcarrierpower,                            dBm                                            -119.1
                        V L - 1 command r e c e i v e rm a r g i n ,     dB                                          26.2

F o re l e v a t i o n so t h e rt h a n 90deg, t h e above d a t am u s tb er e d u c e da c c o r d i n g l y ;t h e
maximum c o r r e c t i o n a t 10-deg e l e v a t i o n was 2.00 dB.


                                                                         3-3
      XA + 35,000 HZ




                           XA   + 10,000 Hz

                                                                                                       FREQUENCIES ARE S-BAND.
                                                                                                       RATES ARE FROM
                                                                                                         THEPROGRAMMABLE
                                                                                                         OXILIATOR CONTROL ASWBLY.




                           F i g u r e 3-2.           V i k i n gL a n d e rU p l i n kA c q u i s i t i o n       Sequence


450                    I                          I                        I                       I                      I

                                                                                                                                     ,   - -152




                                                                        YEAR



                F i g u r e 3-3.              P r e d i c t e dD o w n l i n kS i g n a lL e v e lF r o mV i k i n gL a n d e r      1


                                                                           3-4
          Over t h e y e a r s o f t h e p r i m a r y m i s s i o n , t h e o p e r a t i o n a l c o m p l e x i t i e s               o f the
Networkrangingsystemfrequentlyresulted                                          i n the loss ordegradationofthe
r a n g i n gd a t a .T h i ss i t u a t i o ni m p r o v e d           i n l a t e ry e a r s ,       and t h eN e t w o r kp r o v i d e d
excellentradiometricdatareturn                                   and h i g h - q u a l i t y r a n g i n g d a t a , a s s e e n f r o m
t h er a n g i n gp e r f o r m a n c es t a t i s t i c sg i v e n         i n Appendixes C and D.                        The s u b s t a n t i a l
contributiontotheradio-scienceinvestigationsresultingfromtheimprovement
in r a n g i n g d a t a q u a l i t y i s r e f l e c t e d        i n theradio-sciencediscussion                                  i n Sub-
section II-A.


B.       CONFIGURATIONS

         The b a s i c N e t w o r k c a p a b i l i t i e s r e q u i r e d t o s u p p o r t t h e           VLMM f o l l o w :

          (1) T e l e m e t r y p r o c e s s w o e l e m e t r y u b c a r r i e r s i m u l t a n e o u s l y d a t a
                                :           t t                 s                   s                         at
              r a t e s o f 8.333 b i t s / s uncoded              and         up t o 1000 b i t s / s b l o c k              coded.

         (2)            command
                  Command:                           a s i n g l es p a c e c r a f ta t        a b i t r a t eo f      4 bits/s.

         (3)                      g
                  Tracking: enerate                                                      a d                    r       v
                                                        S-band d o p p l e r a n g i n g n d i f f e r e n c e d a n g e e r s u s
                  i n t e g r a t e dd o p p l e r     (DRVID) r a d i o m e t r i c d a t a .

          (4)            o        s       N      s     a c             b
                  Monitor: utputhe tandard etwork tatus nd onfiguration locks.

          The ways i n w h i c h t h e s e r e q u i r e m e n t s w e r e t r a n s l a t e d i n t o a typical station
c o n f i g u r a t i o n (DSS 1 4 a tG o l d s t o n e )a r e     shown i n F i g s . 3-4 t h r o u g h 3-7.

           The s t a n d a r d 64-m   DSS          c o n f i g u r a t i o nf o rt e l e m e t r yi s      shown i n F i g . 3-4.       t
                                                                                                                                        I
i s o b v i o u st h a tt h eB l o c kD e c o d e rA s s e m b l i e s               (BDA) r e q u i r e d f o r t h e h i g h e r  16-
k b i t s / sb l o c k - c o d e dd a t ar a t e so ft h eV i k i n gO r b i t e r sw e r ed e l e t e d .                    In other
respects, a s t a n d a r d s t a t i o n c o n f i g u r a t i o n              was used.

         The t r a c k i n g c o n f i g u r a t i o n r e q u i r e d t o g e n e r a t e r a d i o m e t r i c d a t a i s             shown
i n F i g . 3-5.

        P r o v i s i o n f o r manual commanding t h r o u g h t h e t e r m i n e t c o n n e c t e d t o b o t h                          com-
mand p r o c e s s o ra s s e m b l i e s (CPA) i s a p p a r e n t i n t h e command c o n f i g u r a t i o n o f
F i g . 3-6.

          M o n i t o r and o p e r a t i o n s c o n t r o l p r o v i d e d by t h e c o n f i g u r a t i o n i n F i g . 3-7
affordedthehighdegree                          o f interactive control between the                               NOCC and t h e DSS r e -
q u i r e df o rt h es h o r tp a s s e s ,c o m p l e xa c q u i s i t i o np r o c e d u r e s ,a n dm a n u a l             commanding
proceduresthatresultedfromthereducedscopeofVikingoperations                                                               in this period.


C.       REAL-TIME LINK TO THE UNIVERSITY O F WASHINGTON

           E a r l y i n 1982, D r . James T i l l m a n o f t h e U n i v e r s i t y o f W a s h i n g t o n p r o p o s e d   a
r e a l - t i m e da,ta l i n k between JPL a n d t h e U n i v e r s i t y                                     U )
                                                                                     o f Washington ( W t o t r a n s f e r
t h e VLMM t e l e m e t r y d a t a d i r e c t l y t o U f o r p r o c e s s i n g and d i s p l a y .
                                                          W                                                          I was envisaged
                                                                                                                     t
thattheseandothersupplementarydatawouldeventuallybetransmittedfrom                                                             UW
t o t h e S m i t h s o n i a n A i r and Space Museum i n Washington, D.C., f o r d i s p l a y t o t h e
generalpublic.


                                                                         3-5
           64-m
                                                   MDA                  PPR
       1   ANTENNA                                   4
                                                     1
                                                                         4                                    1




                                                             -
                  uwv         20-kw             BLOCK IV
                              TXR
                                               -- -- - -- -
                                                EXCITER
                                                                   4

                                            * DOPPLER                  MDA
                                   I          EXTRACTOR




RCVR
                   t
                  SPD
                  T M
                   W
                              I I
                              3

                                  4
                                                  SDA 3                SSA Y    -       TPA 1

                                                  SDA 4                 SSA 2   "---)                  sscs
                               PPR


                                                    EXC


                     ANGLES
                                                 N'"
                                                                                                                  CMF, CPA, M D A ,
                                                     t
                                               DOPPLER
                                                                                                                  TPA CONTROL

                                               EXTRACTOR




           F i g u r e 3-4.       V i k i n gL a n d e rT e l e m e t - r yC o n f i g u r a t i o n    - DSS 1 4




                                                                 3-6
                                                                                                                                                           DSS/GCF
                                                                                                                                                           INTERFACE


                                                                                                                                                               I
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                                                                                                                                                               I
                                              -L
                                             4U
                                              RCVR 1




                                             7n
                                              RCVR 2
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                                                                      DOPPLER
                                                                      EXTRACTOR
                                                                      ELK 111
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                                                                                                        DOPPLER
                                                                                                        COUNTER
                                                                                                        1
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                                                                                                                                                               /8
                                                                                    BLOCK Ill           COUNTER
                                                                                                                                     TERMINET

                                     S



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                                                                                                                                                     PRDX      I
                                    I               ODA   &
                   DATA
                                                                                                    WEATHER
                                                                                                    DATA                               STRIP CHART



     ANTENNA      ANTENNA
                  SERVO                                                                                               IONOSPHERIC
     MECHANICAL                                                                                                       DATA



                          F i g u r e 3-5.     V i k i n gL a n d e rT r a c k i n gC o n f i g u r a t i o n           - DSS        14
                                                                                                                             DSS/GCF
                                                                                                                             INTERFACE



                                    1                                                                                            I



                                                                                                          TERMINET


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                                                                                                                            -1

                                                                                                                                 I
    A   BLOCK 111 EXCITER USED DURING
        BACKUP MODES ONLY
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                                        F i g u r e 3-6.   V i k i n g Lander Command C o n f i g u r a t i o n - DSS 1 4
                                                       """"""
                                                       r"""""
                          DSS INTERNAL
                          INTERFACES
                                                                                                    D MC
                                                                                                                                               1

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             TLM

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                                                       I

            CMD     CMA



    CMA     CMD
                                                                                          t         .)                             SMC 28

          DOPPLER
                                                                                                               *              i Z
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                                                                                                   920
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                                                                                     PAPER-TAPE
                                                                                     PUNCH
                                                                                                    A

                                                                                                           PAPER-TAPE
                                                                                                           READER
                                                                                                                                    1
                                                                                                                                 TERMINET



                                                                                                    v


                                                                                   w
                                                              DIS II
                                                              ANALOG                      I
                                                              DIGITAL                         SIGNAL COUPLER
                                                              INTERFACE




                                                       L______________________J
                      F i g u r e 3-7.         Viking L a n d e rM o n i t o ra n dO p e r a t i o n sC o n t r o lC o n f i g u r a t i o n       - DSS 1 4
           The p l a n n e dc o n f i g u r a t i o n i s shown i n F i g . 3-8.            I n t h ec e n t r a lc o m m u n i c a t i o n s
 t e r m i n a l (CCT) a t JPL, t h ei n c o m i n gV i k i n gL a n d e re n g i n e e r i n gd a t a( 8 - 1 / 3b i t s / s )
 a n ds c i e n c ed a t a     (1 k b i t s / s ) was f e d t o a d a t a s e t w i t h FTS d i a l - u p c a p a b i l i t y t o
 a c o r r e s p o n d i n gd a t as e ta t        W
                                                   U.    The d a t as t r e a m was b u f f e r e d a t t h i s p o i n t p r i o r
 toentryintothe                 UW d a t ap r o c e s s o r .     In a d d i t i o nt ot h er e a l - t i m e       link described
 above, theDataRecordsGenerator                             i n t h e CCT a t JPL c o n t i n u e d t o r e c o r d t h e           incom-
 i n g d a t a t o make t h e I D R f o r n o n r e a l - t i m e d e l i v e r y t o       UW.

          By May 1982, thereal-timesystemhadbeensetup,andon                                                         May 1 4 r e a l - t i m e
V i k i n gL a n d e rd a t a       was t r a n s m i t t e d t o UW f r o m JPL.                  The p u r p o s eo ft h et r a n s m i s -
s i o n was t o t e s t t h e 4 . 8 - k b i t s I s d a t a - l i n k m o d i f i c a t i o n s a t           JPL, and t o t e s t t h e
c a p a b i l i t yo fr e c e i v i n g   a n dd e c o d i n gt h ed a t aa t           W
                                                                                        U.           T h i s was accomplishedsuccess-
f u l l y o ni n t e r i md a t ap r o c e s s i n ge q u i p m e n tt h e na v a i l a b l ea t              W
                                                                                                              U.         ByOctober1982,
regular Viking transmissionswere taking place using                                               a permanent i n s t a l l a t i o n a t
uw.
      Implementationofthe     link to the Smithsonian                                       was w e l l advanced by October
1982,and   planswerebeing     made t o o p e n t h e d i s p l a y                           i n t h e A i r and Space Museum
to the general public  by t h ee n d o f t h e y e a r .


 D.   S-BAND
AUTOMATIC DOWNLINK

         D u r i n gt h eV i k i n ge x t e n d e dm i s s i o n s ,    one o f t h e two V L - 1 command r e c e i v e r s
failed,leavingonly                    Command R e c e i v e r 2 (CR2) i n s e r v i c e f o r t h e V i k i n g                    Lande?
M o n i t o rM i s s i o n .     CR2 h a d a t e m p e r a t u r ep r o b l e mt h a tc a u s e d           i todroplock
                                                                                                            t                            when
i t s case    temperature        exceeded            25OC.         As a r e s u l t ,d o w n l i n kt r a n s m i s s i o np e r i o d s
thatrequiredactivationofthespacecrafttransmitterswerelimitedto                                                                     onehour
toavoidthetemperature-sensitiveoperatingcondition.

          I n November 1981, A. B r i t t i n g , Jr., p r o p o s e dt h a ta na u t o m a t i cs e q u e n c eb e
d e s i g n e d f o r VL-1, one t h a t w o u l d a c t i v a t e t h e d o w n l i p k t r a n s m i s s i o n            i n t h ee v e n t
of failureofthe                  one r e m a i n i n g command r e c e i v e r .           Thesequencewouldinclude                         a
timerinitiatedatthe                        end o f e a c hs u c c e s s f u ld o w n l i n kt r a n s m i s s i o n .        I f t h et i m e
s i n c et h el a s tt r a n s m i s s i o ne x c e e d e d    a p r e s e l e c t e dv a l u e( e . g . ,            2 mo), t h e n e x t
downlink would be initiated automatically and repeated at regular intervals
t h r o u g h December 5, 1994, a t w h i c h t i m e t h e e x i s t i n g h i g h - g a i n a n t e n n a E a r t h -
pointing program would expire.

         Such a scheme was c o n s i d e r e d a n e x p e d i e r l t t o e n s u r e a continuumofregular
 &1
V - data in theeventof          a p o t e n t i a l l o s s o f uplink c a p a b i l i t y .

          Approvalfor a waivertotheNationaland                                  NASA D i r e c t i v e (NMI 2570.3) r e -
q u i r i n g o n / o f f telecommand c a p a b i l i t y f o r NASA s p a c e c r a f t was s o u g h t o n t h e
g r o u n d st h a tt h e     VL-1 w o u l dc o n t i n u et ou s ei t sa p p r o v e dt r a n s m i s s i o nC h a n n e l                 13,
and t h et r a n s m i t t e rw o u l db e       programmed t o s h u t down i n 1996.                        A d d i t i o n a l l y ,s h o u l d
t h e programmer f a i l , i was c o n s i d e r e d t h a t t h e
                                     t                                           RTG p e r f o r m a n c ew o u l dh a v e             de-
graded by 1996 t o t h e p o i n t w h e r et h e RTG p o w e r o u t p u t c o u l d n o t s u p p o r t f u r t h e r
VL-1 t r a n s m i s s i o n s .     The w a i v e r was approved o n January 20, 1982                        (Refs. and3-1
3-2).        The a u t o m a t i cp r o g r a m was t r a n s m i t t e d t o VL-1 on January 2 7 , 1982.




                                                                      3-10
    [
    -                             VIKING SUPPORT DSS's                           \     -TRANSMISSION-                        \<                                                         JPL - PASADENA, CALIFORNIA                                                                                      \
    IDSSC's (GOLDSTONEIMADRIDICANBERRA)                                   1                                                     ;CF 20 - WCSC CENTRAL C O W TERMINAL (BLDG B O )                                                                        ' M I S S I O N CONTROLCENTER
                                                      VOICE LOOPS
                                                                       "-
                                                                      - zLuz-                    VOICE LOOPS
                                                                                                                                            UEL (213) ?54-5801/5802/58m)                                                  ,'<
                                                                                                                                                                                                                            ;,
                                                                                                                                                                                                                            o
                                                                                                                                                                                                                                  I   ,-YlEC       I
                                                                                                                                                                                                                                                        1 (BLDG 23G-113)
                                                                                                                                                                                                                                                        I


                                                     DSNCOORDNET,          o"o         -         DSN COORD NET
                                                                                                                            I
                                                                                                                            I
                                                                                                                                               VOICE
                                                                                                                                                 VOICE                              DSN TRK NET
                                                                                                                                                     VOICE                         DSN COORD NET
                                                                                                                                  VOICE,                           SWITCHER
                                        -
                                                                                                                                                                                                                                                                                                    -




                                                                                                                        I
                                                                                                                                                                                                                                                         ""
                                                                                                                                                                                                                                                        L"
                                                                                                                                                                                       DSN HSDINTERFACE
                                         COMM
                                          MON
                                                                                                                                                 f
                                                                                                                                                                           -                                                                       GCF STAR
                                                                                                                                                                                                                                                                                                    \

                                     *                                                                                                                                                 NETWORK                              ECS                        $r
                                                                                                          Mn
                                          FMTR

                                                                                                          L:
                                                                                                                                                                           "lTCH                                          COMPUTER
                                          (CMF)                             b"-                61"HSDL 7 . 2 K FDX
                                                                                           VK LOR 8 Ib-1; S/C     DATA
                                                                                                                                                                                 *     ENCOMR/
                                                                                                                                                                                       DECODER                           "C
                                                                                                                                                                                                                        T -
                                                                                                                                                                                                                                                        I,           DRG
                                                                                                                                                                                                                                                                   COMPUTER


    I
                                                                           -       1
                                                                                                                "
                                                                                                                        -I                                                               (NED)                            \
                                                                                                                                                                                                                              I



                                                                                                                        I                                                  -
                                                                                                                                                                                 +
                                                                                                                                                                                         (NED)
                                                                                                                                                                                       ENCODER/
                                                                                                                                                                                       DECODER
                                                                                                                                                                                                    -                                                        / "
                                                                                                                                                                                                                                                             1"

                                                                                                                                                                                                                                                            '!   VIKING (8   ID/
                                                                                                                                                                                                                                                                                           \

                                                                                                                                                                                                                                                                                   1K) T L M
                                                                                                                        I                                                                                                                                        DATA
                                                                                                                                                                                                                                                                   RECORDS     TO U N l V      !
                                                                                                    FTS (2) WIRE DIAL                                                                                                                                            O WASH VIA
                                                                                                                                                                                                                                                                  F       AIRMAIL               I
                                                                                                    HSD (4.8 KB/S)                                                                                                                                                                             J
                                                                                                                                                                                                                                                                         g-"
                                                                                                                                                                                                                                                             L"
                                                                                                    SYNCHRONOUS
                                                                                                    TX MODE
                                                                                                    ""

                                                                                                    VK TLM + FILLER
                                                                                                    DATA DSN 1200/22
                                                                                                    BIT BLOCKS


                                                                                                                        I
w                   SMITHSONIAN INSTITUTE         - WASHINGTON.      LC.                                                I                                                       UNIVERSITY OF WASHINGTON (SEATTLE WASH.)
                                                                                                                                                                                                                                                                                                        -
= I
        NATIONAL AIR AND SPACE MUSEUM

                                                                                     I
                                                                                                                                FTS-VOICE (206)543-0500. HARRY EDMOND




                                                                                                                                                                                                         -I
          V L R
         " K G J
        I       DATADISPLAY
                   *ED 512
                              I
                                                                                                                                                 DIAL-UP



        I
        I       COLORIMAGE    I                                                                                                                         FTS-DATA
                                                                                                                                                                                                                                               I
                 PROCESSING
                  TERMINAL    I                                                                                                                                                        INTEL
                                                                                                                                                                                                                          VIKING
                                                                                                                                                                                                                           SYSTEM
                                                                                                                                                                                       MICRO
                                                                                                                                                                                                                          PRIME 4W
                                                                                                                                                                                     PROCESSOR
                                                                                                                                                                                                                         COMPUTER




            1    COMPUTER
                                                                                                                                                 DIAL-UP



    I
    NOTES:        A R A N N E D V I K I N G LANDER SUPPORT I-PASS/
                      WK WITH MAX OF I HR T L M DATA
                                                                                   I
                                                                                                                   L                                  SET

                                                                 A DIAL-UP DATA CKT AND
                                                                              CONNECTION                    PARALLEL                             w
                                                                     DATA STREAM SWITCHING TO BE ESTABLISHED BY
                                                                     GcF   2occTON   REAL-TIME REaUEST      NOC(BASED
                                                                                                                                  A OCT 82 IS P L W N E D DATE FOR V I K I N G REAL TIME DATA     A N O ATRS OR POSTPASSREPLAYDATA      TO BE ROUTED TO U N I V O F WASHINGTON
                                                                                                                                               UNl
                                                                                                                                      SWITCHING T OV         OF WASH                                                   E
                                                                                                                                                                                                      RECALL DATA T O B PROVIDED O N IDR O N L Y
                                                                     O N TIME IDENTIFIED IN VIKING PASS MSG W E )
                               COMMAND
                                  WINDOW
                                                                 A VK LDR IDR                     ToBE PROV,DEUNIV                      6CS
                                                                                                                                      JPL (CCT)   C W W T E R WILL BE CONFIGURED/VIILIZED         A
                                                                                                                                                                                                 ECSALLFOR             TO
                                                                                                                                                                                                                    UNlV
                                                                                                                                                                                                                  SWITCHING                          ALL
                                                                                                                                                                                                                                   OF WASH, DSS TO ADDRESS   VKG LDR T L M
                                                             ,
                                                                                                                                      TO SWITCH VK LDR TLM DATA IN REAL TIME TO U N l V O F            DATA TO DESTINATION CODE MI--               --
                                                                                                                                                                                                                                       ECS OPERATOR TOREROUTE DATA WITH
                                                                                                                                      WASHINGTON VIA FTS DIAL UPCKT INTERFACE                         ANY UNUSED AMES ALT ROUTE DESTINATION CODE (An THROUGH AD) UTILIZING
                                                                                                                                                                                                      PORT 10 ATTHE HIGH SPEED LINE SWITCH(HLS)




                                                       F i g u r e 3-8.                    R e a l - T i m eD a t aT r a n s f e rt oU n i v e r s i t y                                 o f Washington
          As o f t h a t d a t e , t h e a u t o m a t i c         S-band d o w n l i n k t r a n s m i s s i o n was a c t i v a t e d
after eight consecutive downlink intervals elapsed without an uplink reception.
Because o f t h e d i f f e r e n c e             i n t h e l e n g t h s o f Mars     and      Earthdays,theinterval
b e t w e e nd o w n l i n kt r a n s m i s s i o n sv a r i e d        f r o m 7 t o 8 E a r t hd a y s .           Thus, anauto-
m a t i c d o w n l i n k was i n i t i a t e d between 56 and 6 4 days a f t e r t h e p r e v i o u s d o w n l i n k
hadbeencompleted,unless                             a s c h e d u l e du p l i n kh a db e e ns u c c e s s f u l l yc o m p l e t e d .

         The program was i n t e r r u p t e d a n dt h ec o u n t e rr e s e t      t o zeroatanytime                in
theeventthatthe              absence o f a n u p l i n k was       d.ue   t o t h e u n a v a i l a b i l i t y o f antenna
t i m e ,r a t h e rt h a n a VL-1 r e c e i v e r f a i l u r e .


E.            L1
         THE V - RECOVERY
                       EFFORT

          A l t h o u g ht h eV i k i n gL a n d e r        M o n i t o r M i s s i . o nc o n t i n u e ds u c c e s s f u l l y f o r several
y e a r s ,s i g n s     o f a s e r i o u sb a t t e r yp r o b l e mb e g a nt o             show i n l a t e 1981.             The a d v i c e
o f experts i n this field from all over the country suggested                                                    a change t o t h e b a t -
t e r y - c h a r g i n gs t r a t e g yd e s c r i b e d    i n Section 1 ; thisstrategyinvolveddischarging
                                                                                     1
thebatteriesto                     a known v o l t a g e r a t h e r t h a n f o r         a f i x e dt i m e .        A command sequence
i n t e n d e d t o make these changes t o t h e b a t t e r y - c h a r g i n g sequence was u p l i n k e d b y
DSS 43 on November 19, 1982,                          and an      a c q u i s i t i o n sequence f o rt h ee x p e c t e d             down-
l i n k was c a r r i e d ou$

        However, t h ee x p e c t e dd o w n l i n kd i dn o ta p p e a r ,                    and t h e P r o j e c t d e c l a r e d       a
s p a c e c r a f t emergency on November 20, 1982.

      I was assumed t h a tt h eb a t t e r yu n d e r - v o l t a g e
       t                                                                             (UV) s w i t c h , a n d t r i p p e d , and
theProjectdirecteditsstrategyfor                                       subsequentpasses   toclosingthe                    V
                                                                                                                        U switch
and i n c r e a s i n g t h e b a t t e r y - c h a r g i n g c y c l e s .

          However, s h o r t l y t h e r e a f t e r ,         i was r e c o g n i z e d t h a t t h e
                                                               t                                                   new b a t t e r y - c h a r g i n g
sequence hadbeen w r i t t e n i n t o s p a c e c r a f t memory l o c a t i o n s o c c u p i e d b y t h e l a n d e r
high-gain ntenna ointing arameters.
                a            p            p                                I f o l l o w e d , ,t h e r e f o r e ,t h a tt h e
                                                                            t                                                           VL-1
antenna was n o l o n g e r p o i n t i n g t o E a r t h . U s i n g t h e o l d , L a n d e r s i m u l a t i o n p r o -
gram, a new s e t o f a n t e n n a p o i n t i n g a n g l e s                  was developedbasedontheerroneous
b a t t e r yp a r a m e t e r st h e nr e s i d i n g       i n thelandercomputer                      memory. The l a n d e ra n t e n n a
t h e nc o n t i n u e dt oe x e c u t er e g u l a ra n t e n n ap o i n t i n gs e q u e n c e s ,b u tt h e s ed i dn o t
crosstheEarth-Mars                     l i n e e x c e p tf o r t u i t o u s l y    o n s p e c i f i c daysandtimes.

           Most o ft h ef o l l o w i n gr e c o v e r ys t r a t e g y       was based      on   t h i s assumption.    As
shown i n t h e c h r o n o l o g y o f events i n Appendix F, many a t t e m p t s w e r e made t o t r a n s -
m i t commands t o t h e s p a c e c r a f t , c l o s e             t h e UV s w i t c h , andundo      t h e erroneous
p o i n t i n g p a r a m e t e r s i n thecomputer.

         Thisinvolved a great deal of                     manual commanding a t t h e DSSs u s u a l l y i n much
l o n g e r sequences t h a n h a d p r e v i o u s l y b e e n u s e d         o n t h eV i k i n ge x t e n d e dm i s s i o n s .
Some m i s t a k e s r e s u l t e d i n l o s t p a s s e s , b u t t h e s e w e r e q u i c k l y r e c t i f i e d ,      and a f t e r
t h e f i r s t week o r t w o , Networksupport                  f o r t h e l o n g manual command sequencesandthe
high-powertransmitterrunningat                                W
                                                        80 k was v e r y good.




                                                                      3-12
     A t e l e c o m m u n i c a t i o n su p l i n ka n a l y s i s showed t h a t , a t a t r a n s m i t t e r power o f
100 k n o m i n a l ( a c t u a l power o f 80 kW), t h e r e was a 10- t o 14-dB m a r g i n f o r com-
    W
mand w i t h t h e p o i n t i n g a n g l e p a s s i n g t h r o u g h t h e s i d e l o b e s o f t h e              V L - 1 antenna
polardiagram.There                         was noconcern f o r l i m i t a t i o n s i n t h e u p l i n k m a r g i n              on t h i s
b a s i s .N e v e r t h e l e s s ,b e c a u s eo f . u n c e r t a i n t y     i n t h ep o l a r i z a t i o ne f f e c t sa ta n g l e s
well off the main                   beam o f t h e        VL-1 antenna,sometransmissionswere                            made i n t h e l e f t
c i r c u l a r and l i n e a r modes, as w e l l as t h e n o r m a l r i g h t c i r c u l a r p o l a r i z a t i o n .

     By t h e end o f December 1982, t h e s p a c e c r a f t h a d n o t r e s p o n d e d t o t h e s e
repeated efforts to initiate    a downlink, and f u r t h e s e f f o r t s weresuspended
pending an in-depth investigation by Martin             Company engineers.

         Although a l l o p t i o n s f o r i m p r o v i n g t h e u p l i n k m a r g i n h a d b e e n t r i e d ,                i was
                                                                                                                                     t
d e c i d e dt h a tt h eu p l i n km a r g i n       was adequateeven w i t h theantenna o f f p o i n t .                                t
                                                                                                                                           I
was t h o u g h t t h a t t h e        L1
                                     V - antennamightnotbepointing                                in the direction indicated
bythesimulation                  program,and           t h a t t h e V L - 1 computerhadalsobeenswitched                                  off
              V
b yt h e U s w i t c h .O t h e rf a i l u r e             modes were also         proposed.              The outcome o ft h e
Martin-JPLinvestigation                     was a s t r a t e g y i n v o l v i n g r e c o n d i t i o n i n g t h e b a t t e r i e s ,
reinitializing the lander                      c o m p u t e r ,c l o s i n gt h e   V
                                                                                    U s w i t c h ,a n dv a r i o u so t h e r
lander housekeeping activities.

         Thisstrategywouldrequire                          much longerNetwork command sequences, repeated
many t i m e s d u r i n g t h e l i m i t e d v i e w p e r i o d s . I became o b v i o u s t h a t t h i s
                                                                       t                                      was be-
yond t h e c a p a b i l i t y o f t h e e x i s t i n g manual command system,    and         some form o f auto-
m a t i n g t h e command sequences wouldbenecessary.

          Over t h e p r e c e d i n g s e v e r a l y e a r s ,       a manual command procedurehadbeenused                             in
which a maximum o f 24              commands             c o u l d b e sentmanually             f r o m t h es t a t i o n .   The s t a -
t i o n r e q u i r e d 2 m i n u t e sp e r command t o l o a d and v e r i f y .                    Once t h el o a d e ds e t   of
commands      was      t r a n s m i t t e d ,t h ep r o c e s sh a dt ob er e p e a t e df o r             any f u r t h e r command
sequences.

          S i n c et h e new V L - 1 s t r a t e g y c a l l e d f o r command seauences o f a t l e a s t 30 com-
mands i n l e n g t h t o b e t r a n s m i t t e d e v e r y      20 minutes, i was a p p a r e n tt h a ts u c h
                                                                                   t                                         a
s t r a t e g y was tootimeconsumingand                      t o o prone t o e r r o r s f o r use i n t h e t h e n - c u r r e n t
command procedures.

          Therefore, new s o f t w a r e was developed t o p e r m i t t h e MCCC m u l t i m i s s i o n ' com-
mand system t o c o n v e r t 360-75 card-based command sequences i n t o f i l e s t h a t c o u l d
b ea c c e p t e db yt h e          CPA a t each DSS.   A s p a c e c r a f t I D p r e v i o u s l yu s e df o r HELIOS
s i m u l a t i o ne n a b l e dt h e   N C t o overlayViking"standardsandlimits"tables
                                         OC                                                                             on
t h e unused HELIOS tables,andcause                   t h e CPA t o respond t o c o n t i n u o u s t r a n s m i s s i o n
o f V i k i n g command f i l e s f r o mt h e MCCC.        T h i s c a p a b i l i t y was f i r s t t e s t e d w i t h
CTA 2 1 andworked s a t i s f a c t o r i l y i n a l l r e s p e c t s .

         T h i s new c a p a b i l i t y was u s e d o p e r a t i o n a l l y f o r t h e f i r s t t i m e o n F e b r u a r y        1 ,
1983, t o t r a n s m i t 30        commands      every 20 m i n u t e s f o r t h e t o t a l d u r a t i o n o f t h e              DSS
43-viewperiod.                  The f i r s t command l o a dr e s t a r t e dt h e             VL-1 computer         and        initial-
i z e dt h eb a t t e r y - c h a r g i n g  sequences.           The second command c l o s e dt h e U s w i t c h         V
and p a r k e d . t h ea n t e n n a .      The f i r s t p a r t o f t h i s l o a d        was t r a n s m i t t e do v e r DSS 43
and t h e second p a r t o v e r DSS 63 onFebruary                           10. The t h i r d l o a d o n F e b r u a r y           11




                                                                   3-13
t u r n e do nt h ed o w n l i n k ,a n dt h es t a t i o nc a r r i e do u tt h ea p p r o p r i a t ed o w n l i n k
search.        A l l t h i s was accomplishedbyFebruary                                   1
                                                                                        1 , 1983, w i t h o u t any      appearance
o f a downlink.            Two f u r t h e rs t r a t e g i e s        were    proposed.               The f i r s t o f these was t o
change t o t h e s p a r e T W T A - m o d u l a t o r / e x c i t e r s t r i n g , e v e n t h o u g h t h e r e        was n o e v i -
dence t o s u g g e s t t h a t t h e o r i g i n a l s t r i n g h a d f a i l e d .                  These commands weresent
onFebruary 16, but nodownlinkcouldbefound.

          The second s t r a t e g y p r e s u p p o s e d t h a t       t h e a n t e n n a p o s i t i - o n and thecomputer
i n s t r u c t i o n s wereout o f a l i g n m e n t , p o s s i b l y b e c a u s e t h e a n t e n n a s t u c k o r s l o w e d
d u r i n ge a r l i e rr e p o s i t i o n i n g   sequences. The antenna was d r i v e n t o i t s l i m i t s t o
r e a l i g n t h e computerandantenna                     a t a common r e f e r e n c e p o i n t , andthen moved t o
a nE a r t h - p o i n tp o s i t i o n .        A d o w n l i n k was t h e na c t i v a t e do nF e b r u a r y        25.

         The c o r r e c t u p l i n k commands weresentonFebruary        18 t o r e p o s i t i o n t h e an-
t e n n a ,a n dt h ed o w n l i n k" f l a g " was sentonFebruary     25; t h i s was f o l l o w e d by a ,
downlinksearchoverGoldstone.                      No downlinkcouldbefound.

        Next, a h i g h l y s e n s i t i v e w i d e - b a n d w i d t h s p e c t r u m a n a l y z e r u s e d f o r R F I d e t e c -
t i o n purposes a t Goldstone was a l s ou s e df o rt h es e a r c h .                               The t h r e s h o l d d e t e c t i o n
s e n s i t i v i t yo ft h i si n s t r u m e n t  was -186              -,dBm, but s u b s e q u e n t n a l y s i s f h e
                                                                                                               a             ot
resultingintegratedspectrarevealednothing.

    A t thispointtheProject             announced t h a t no f u r t h e r a c t i o n was warranted
and i was presumed t h a t t h e l a n d e r
    t                                        was u n a b l e t o communicate w i t h E a r t h .




                                                                  3 -14
                                                    IV.                     RETURN
                                                                 VLMM SCIENCE


A.      R A D I O SCIENCE

         Duringthecourse                   o f theVikingMission,             a substantial contribution to the
f i e l d o f radioscience                 wasmade   by i n v e s t i g a t o r s u s i n g t h e o r b i t e r s o r l a n d e r s
or both.

        Specific areas              i n whichpapershavebeenpublishedare:

          (1) R a n g i n gv a l i d a t i o n .

          (2) R e l a t i v i t y i n v e s t i g a t i o n .

          ( 3 ) D y n a m i c a lc o n s t r a i n t s      o f Mars.

          ( 4 ) S o l a r - w i n ds c i n t i l l a t i o n .

          (5) Shape o f Mars.

          ( 6 ) M a r sg r a v i t y .

          (7) Radiobeacon                  f o r deepspace            navigation.

          (8) G r a v i t y waves.

          ( 9 ) S o l a rg r a v i t y .

        (10) S o l a r - w i n de l e c t r o nd e n s i t y .

         1 )
        ( 1 Ephemerisrefinement.

Some o f t h i s w o r k c a r r i e d o v e r i n t o t h e VLMM, p a r t i c u l a r l y i n t h e a r e a s
o f g r a v i t a t i o n a l t h e o r y andephemerisdevelopment.

          VLMM r a d i o s c i e n c e d a t a g e n e r a t e d  by theNetwork was g a t h e r e d o v e r a p e r i o d
o f t e n s u c c e s s f u l V L - 1 r a n g i n gp a s s e sa n dd e l i v e r e da s           a package t o t h e i n v e s t i -
g a t o r s I Shapiroand
                 .                     R. Reasenberg a t t h e M a s s a c h u s e t t s I n s t i t u t e                o f Technology
and t o W. M i c h a e la tt h eL e w i sR e s e a r c hC e n t e r .E a c hp a c k a g ed e l i v e r e dc o n t a i n e d
t h ef o l l o w i n gi t e m s :

        (1)      A t a p ec o n t a i n i n g a M a s t e rT r a c k i n gD a t aF i l eo fd o p p l e ra n dr a n g i n g
                 d a t af r o mt e ns u c c e s s f u lp a s s e s .

        (2)      A r a n g i n gc a l i b r a t i o n       summary and a s e t of p u n c h e dc a r d sc o n t a i n i n gt h e
                 summary d a t a .

        (3)      A c u r r e n t s e t o f Range "Z"
                                            c o r r . e c t i o n st oa d j u s tt h e                       measuredrange            to
                 thestationreferencelocation.

        (4)      A COPY o f t h e p a s s f o l d e r c o n t a i n i n g         a l o go fs t a t i o ne v e n t sd u r i n ge a c h
                 pass.


                                                                      4-1
          (5)      A copy o f t h e l a t e s t s t a t u s r e p o r t           o nt h e     VLMM w r i t t e n by t h e P r o j e c t
                   Engineer.

          (6)      A commentary s u m m a r i z i n g t h e q u a l i t y o f t h e d a t a r e t u r n     and n o t i n g
                   significant events for each             pass d u r i n g t h e p e r i o d c o v e r e d b y t h e
                   package.

 T h i s s u b s t a n t i a l package o f d a t a was assembled b y one o f t h e e n g i n e e r s s u p p o r t i n g
 t h e VLMM on a p a r t - t i m e b a s i s .    Much o f the.data was h a n d w r i t t e n t o save c o s t s .
 Seven packages c o n t a i n i n g t h e d a t a d e s c r i b e d abovewere t r a n s m i t t e d t o t h e i n v e s t i -
 gatorsduringtheperiod                 1980 t o 1982.

      Two r e c e n t p a p e r s d e s c r i b i n g t h e V i k i n g R e l a t i v i t y E x p e r i m e n t a r e g i v e n    in
Refs. 4-1 and 4-2.           A n a l y s i s o f r a n g i n gd a t af r o mt h eV i k i n gs p a c e c r a f t ,i n c l u d i n g
the landers, verified             a prediction o f the General Theory of Relativity relating
totheinfluence           o f solar gravity ontheround-triplighttimeofsignalspassing
between Earth andMars.

        The e s t i m a t e d a c c u r a c y o f t h e s e r e s u l t s    was 0.1%basedonobservationsover
a p e r i o do fa b o u t        one y e a r .F u r t h e rr e d u c t i o n   in theuncertaintyofthistestof
g e n e r a l r e l a t i v i t y was dependenton t h e c o l l . e c t i o n a n d r e f i n e m e n t o f a d d i t i o n a l
data.

        More r e c e n t l y , t h e VLMM r a d i o m e t r i c d a t a was usedbyShapiro,                                  et al., to
evaluateevidenceforthetimevariationofthegravitationalconstant                                                                   as a func-
t i o n o'fatomictime.

          In investigatingtheselong-termeffects,precise                                   measurements o f t h e o r b i t a l
p e r i o d s o f E a r t h andMars        (representing a gravitational clock) are                              made w i t h hy-
drogen-maser t i m es t a n d a r d s( r e p r e s e n t i n ga t o m i ct i m e ) .         I n an e f f o r t t o reduce
theresidualsbetweenpredictions                           andmodels,            the quality o f the radio metric
data,thecomputerprograms,                       and t h e m o d e l st h e m s e l v e sa r eb e i n gi n v e s t i g a t e d ,
as w e l l as p e r t u r b a t i o n s o f t h e E a r t h    and Mars o r b i t s b y . t h e g r a v i t a t i o n a l e f f e c t s
o f s e v e r a l a s t e r o i d s and p l a n e t s .


B   .    METEOROLOGY

          Two meteorologyexperimentsensorson                                      V L - 1 were t h e L o c a l AmbientPressure
Sensor     and        t h eL o c a l Ambient        Temperature        Sensor.      Under                   t h el e a d e r s h i po f     D r . James
T i l l m a n o f t h e U n i v e r s i t y o f Washington, t h e l o n g p e r i o d s                         o f c o n t i n u o u sV i k i n g
o b s e r v a t i o n s f r o m these two i n s t r u m e n t s h a v e p r o v i d e d m a j o r i n s i g h t i n t o                   many
M a r t i a na t m o s p h e r i cp r o c e s s e s ,s u c ha sf r o n t a ls y s t e m s ,a n n u a lc l i m a t e                     measure-
ments, i n t e r a n n u a l c l i m a t e v a r i a t i o n s ,          and duststorms.

     Typical daily records of pressure  and temperature from VL-1, whichhavebeen
processed a t UW asdescribed i n Subsection C , a r e shown i n Figs.4-1 and 4-2.

        S i m i l a rd a t ac o v e r i n g a span o f 3 M a r t i a ny e a r s i s shown i n F i g . 4-3.             In
t h i s diagram, 669.0 s o l s e q u a l 687 E a r t h days.             T h i s i s t y p i c a l o f t h ea n a l y t i c a l
datadeveloped by T i l l m a n , and r e v e a l s t h e p r e s e n c e        o f duststorms         i n wide




                                                                      4-2
       9.o
        Oo                                      I                         I                             I                      I
                   (a)




       8.o
        Oo




        O
       7. M
                      o
                 2200 .                      2202 .o                   2204.0                        2206 .o                   o
                                                                                                                          2208 .

       9 .om                        I                  I         I               I               I             I           I
                    (b)




        8 .ooo
                          VL-1




                 2208.0                                                                                                             2216.0

                                                            TIME NORMALIZED TO LOCAL MIDNIGHT, VL-1 sols


F i g u r e 4-1.             T y p i c a lV i k i n gL a n d e r 1 Pressure     (a)
                                                                          Record:            Wednesday, October 6, 1982,           16:04:58;
                             (b) Wednesday, October 1 3 , 1982, 0 3 : 3 8 : 4 4           (Courtesy o f t h e U n i v e r s i t y o f Washington
                             Department o f AtmosphericSciences)
                                                 I                          I                            I



           260 .O

                            VL-I




           240 .o




           220 .o

      Y
      W
                                                                                                                      J
      OL

      2
      4,
      W
       0




       c
       0   260.00                                      I                            I                          I

       P




                    I -




                    )                                  I                            I                          I                         I
                        2208 .o                      2210.0                      2212 .o                     2214.0                2216 .O
                                                              TIME NORMALIZED TO LOCAL MIDNIGHT, VL-I sols


F i g u r e 4-2.            T y p i c a lV i k i n gL a n d e r 1 L o c a l Ambient
                                                                                  Temperature
                                                                                            Record:     '(a) Wednesday, October 6 ,
                            1982, 1 6 : 0 7 : 2 1 ; (b) Wednesday, October 1 3 , 1982, 0 3 : 3 9 : 1 4 (Courtesy o f t h eU n i v e r s i t y
                            o f WashingtonDepartment o f Atmospheric Sciences)
        0 .o




F i g u r e 4-3.
                        I
                      33b .5




                   years.
                                   YEAR 1




                           Lower Daily
                                        669 .O




                                  Plot: Average.    Upper
                                                             I
                                                           1003.5
                                                                       YEAR 2


                                   TIME NORMALIZED TO LOCAL MIDNIGHT, VL-1 sols
                                                                                I
                                                                           1338.O           1672.5




                   V i k i n gL a n d e r s 1 and- 2 L o c a lA m b i e n tP r e s s u r ef o r
                                                                                               I




                                                                                            Plot:
                                                                                                         1
                                                                                                         7
                                                                                                            VL-I




                                                                                                       L YEAR 3
                                                                                                          2007 .O




                                                                                                         3 Martian
                                                                                                         Standard
                   DeviationsofPressureAroundDaily                                Mean a t V i k i n g L a n d e r 1,
                   Which i s a n I n d i c a t o r o f A t m o s p h e r i c D u s t      f o r Values o f
                   Sigma 2 0 . 1 andLongitude                  (Season) (L,)            Between 180 and 300;
                   A f t e r 300, S y n o p t i c Systems G e n e r a t eL a r g eV a r i a t i o n s          Within
                   a s o l atThisTropicalSite(Courtesy                               o f theUniversity o f
                   WashingtonDepartment o f A t m o s p h e r i c S c i e n c e s )




                                                     4-5
perturbationsofthedailypressurepatterns                                           due t o s o l a r h e a t i n g o f a t m o s p h e r i c
d u s t s ,a t ,f o r         example,                 and
                                             1977a 1977b.       Features                     o fi n t e r e s ti d e n t i f i e db y
T i l l m a n a r e shown b y t h e s m a l l p r e s s u r e s p i k e s l a b e l e d               "C" o c c u r r i n g a t a p p r o x i -
m a t e l y1 - M a r t i a n - y e a ri n t e r v a l s . .     These s p i k e s seem t ob ea s s o c i a t e d                w i t h the
passage o f l a r g e - s c a l e d u s t s t o r m s            andappear a t a l m o s tt h e same M a r t i a n season
eachyear.               Because t h e s ed i s t u r b a n c e sw e r eb e i n gs o u g h t              i n t h e 1982 d a t a ,t h e
N e t w o r kr e c e i v e dr e q u e s t sf o r            as much c o n t i n u o u s t r a c k i n g d a t a a s p o s s i b l e t o
maximizethe chance o f r e c o r d i n g t h e s e d a t a f o r f u r t h e r s t u d y                          and a n a l y s i s .


C.           EXPERIMENT*
         IMAGING

          V i k i n g L a n d e r 2 ceased o p e r a t i o n i n February1980because                             o f onboard battery
failure.            A t t h a tt i m eb o t h          cameras were f u l l y a c t i v e a f t e r          3-1/2 y e a r so fM a r s
o p e r a t i o n s ,d u r i n gw h i c ht h e yh a dp e r f o r m e d            2156 camera events(imagingsequences).
F o r t u n a t e l y , b o t h cameras on VL-1 a l s or e m a i n e do p e r a t i o n a l ,a n dc o n t i n u e d                t o per-
f o r m programmed            camera         e v e n t st h r o u g h o u tt h e M
                                                                                 L .
                                                                                 VM           D u r i n g t h e VLMM, .therewere
1 6 4 p o s s i b l ei m a g i n go p p o r t u n i t i e s ,o fw h i c h          88 r e s u l t e d i n images r e c e i v e d and
d e l i v e r e dt ot h ei n v e s t i g a t o r s .            The d i f f e r e n c e i s due m a i n l y t o t h e l a c k o f
availableantennatime                         i n theearlyyearsbecause                      o f h i g h e r p r i o r i t y Voyager
J u p i t e r andSaturnsupport.

           The VL-1 cameraswere a c t i v a t e d by a s t o r e d p r o g r a m t h a t s e t                a l l t h e camera
parametersincludingpointing,                        so t h a t t h e same scene was viewedonceeach                         Mar-
t i a ny e a r .         Comparison o f successiveannual                    i.mages was used t o check f o r d u s t
o r c o n d e n s a t ed e p o s i t i o n o r e r o s i o no v e rt h ei n t e r v a l    o f time.     A r e c e n t example
o fc o m p a r a t i v ei m a g i n g     i s shown i n F i g . 4-4, where t h e t i m e i n t e r v a l b e t w e e n t h e
t w o photos       extended    from   February            1979 ( l e f t ) t o J u l y     1981 ( r i g h t ) .    The s u b j e c t
was a 5-cm p i l e o f s o i l p l a c e d b e s i d e and p a r t l y a t o p a n l l - c m r o c k b y V L - 1 ' s
s o i l - s a m p l i n g arm.Comparison            o f t h e two hotos
                                                                      p               shows that some o f t h e s o i l had
been    removed b yM a r t i a nw i n d st or e e x p o s et h er o c k s .                The s m a l l change i s impor-
tant,scientists               say,   because      t shows t h a td . e p o s i t i o na n dr e m o v a l
                                                   i                                                            o f fine-hate-
r i a l . i s a c o n t i n u i n g c y c l e o n Mars,as         i i s o nE a r t h .
                                                                   t

           The IDRs made b y t h e DSN i n t h e N C c o n t a i n e d t h e l - k b i t / s i m a g i n g
                                                                          OC                                                          and 8-1/3
b i t s l se n g i n e e r i n gd a t a ;t h e y           were d e l i v e r e d t o t h e      Image ProcessingLab(IPL)                   at
JPL f o r p r o c e s s i n g . The IDRs were                    processed         i n t o p r i n t s and d i g i t a l tapes,         and
10 c o p i e s o f e a c h w e r e d i s t r i b u t e d b y t h e            VLMN P r o j e c t t o t h e      s e v e nr e g i o n a l
p l a n e t a r yi m a g i n gf a c i l i t i e st h r o u g h o u tt h e        U.S.A.          The o t h e r sw e r ea r c h i v e d .
I n v e s t i g a t o r s i n variousareashadaccess                           to the continuing flow of                     Mars i m a g i n g
products f r o m t h e s e r e g i o n a l f a c i l i t i e s .

          A r e c e n t L a n d e r 1 p i c t u r e sequence showing a uniqueMarsevent,                                    a duststorm,
i s shown i n F i g . 4-5.                The s e v e n - p i c t u r e sequence was a c q u i r e do v e r a p e r i o d o f
1 6 m f r o mi n d i v i d u a lV i k i n g 'L a n d e ri m a g i n gs e q u e n c e s .
        o                                                                                              Such images a l l o w re-
s e a r c h e r st oo b s e r v et h ey e a r - t o - y e a rs u r f a c e           changes a r o u n d t h e l a n d e r      - changes
t h a th e l pq u a n t i f yt h em a g n i t u d e so ft h eg e o l o g i c a lp r o c e s s e sa c t i n gt o                 shape t h e
s u r f a c e o f Mars.           The p r e d o m i n a n tt y p eo fs u r f a c e          changes a r e due t o d u s t - b o t h
e r o s i o n a l and d e p o s i t i o n a l .         I n t h es i x t h    frame (June          1 4 , 1901), t h ee n t i r e
scene was darkened by the passage of                                   what a p p a r e n t l y was a l o c a l i z e d d u s t s t o r m .
P r i o r t o and a f t e r t h i s image, t h es k y                      and s u r f a c ew e r eb r i g h t e r .   The change i n

*A l i s t i n g o f NASA p u b l i c a t i o n s r e l a t i n g t o t h e V i k i n g O r b i t e r            and L a n d e r i m a g i n g
 experiments i s g i v e n i n Appendix G.

                                                                     4-6
F i g u r e 4-4.   V i k i n gL a n d e r   1 Comparative Mars
                                                             Images




F i g u r e 4-5.   V i k i n gL a n d e r   1 Seven-Picture Sequence




                                        4- 7
apparent brightness of the large boulder                             named " B i g Joe" e a r l y i n t h e m i s s i o n was
due t os e a s o n a lc h a n g e s  i n t h eS u n ' sa n g l e .. A f t e ro n ec o m p l e t eM a r sy e a r ,t h e
Sn returns to the
 u                              same p o s i t i o n i n t h e sky,andimagescanbecompared                              by com-
putertosearchfordifferences.

          The Marsimagingprogram             was t o c o n t i n u e t h r o u g h o u t t h e   VLMM, s y s t e m a t i -
c a l l y r e t u r n i n g images o f t h e same Marsscene,eachMarsyear,                          u n t i l End o f
Mission (1994).




                                                               4-8
                                                                V.      CONCLUSION


               The N e t w o r k h a s b e e n i n v o l v e d        w i t h the Viking Project through its various
    p h a s e ss i n c e i t s i n c e p t i o n i n 1968 t ot h ep r e s e n tt i m e ,                     1983."          Throughoutthepre-
    launchplanningandtheprimemission,theNetworkrespondedtotheproject's
    requirements for support with total                                 c o m m i t m e n ta n da ne x t r e m e l yh i g hs t a n d a r do f
    p e r f o r m a n c e .T h i s     was a c h i e v e d u n d e r t h e d i f f i c u l t - c o n d i t i o n s o f l i m i t e d s t a f f ,
    o b s o l e t eh a r d w a r ea n ds o f t w a r e ,a n ds p a r s ed o c u m e n t a t i o n .

              F o l l o w i n gt h ep r i m em i s s i o n ,t h e" e x t e n d e d "           and " c o n t i n u a t i o n " m i s s i o n s r e -
!             h
    c e i v etd e         same l e v etle c h n i c a lu p p o r a,l t h o u gc o m p e t i t i ofnarn t e n nta m e
                                          of           s            t             h                o               i
    by f l i g h t p r o j e c t s o f h i g h e r p r i o r i t y r e s u l t e d          i n r e d u c e dt r a c k i n gt i m ef o rt h e
    VLMM. As NASA i n t e r e s t i n t h er e m a i n i n go p e r a t i o n a lV i k i n gs p a c e c r a f td e c l i n e d ,                       t
                                                                                                                                                       i
    became more d i f f i c u l t t o s c h e d u l e a l l t h e r e q u e s t e d a n t e n n a t i m e , e v e n t h o u g h
    s c i e n t i f i c i n t e r e s t i n t h er e d u c e dd a t ar e t u r nq u i c k e n e d .T h i sp l a c e d                   much
    moreemphasis o n a c h i e v i n g "goodpasses''                             t o r e a p maximum r e t u r n f r o m t h e l i m i t e d
    o p p o r t u n i t i e sa v a i l a b l e .

         D u r i n g t h e f i n a l phase o f t h e VLMM, theNetwork was c a l l e d u p o n t o d e v e l o p
    and c a r r y o u t many i n n o v a t i v e t e c h n i c a l and o p e r a t i o n a l s t r a t e g i e s t o s u p p o r t
    theefforttorecoverthe                 VL-1 s p a c e c r a f t .




    *FactsrelativetotheVikingmissionsaregiven                                                 i n Appendix H.


                                                                           5-1
                                       F
                           DEFINITION O ABBREVIATIONS


ANT     antenna

A S
 P      Antenna P o i n t i n g Subsystem

CB      circuit breaker

CCT     C e n t r a l Communications T e r m i n a l

ccu     command c o n t r o l unit

CMA     Command M o d u l a t i o n Assembly

CD
M       Command System

C F
 M      Communications M o n i t o r and F o r m a t t e r Assembly

CO"     communications

COORD   coordination

CA
 P      Command Processor Assembly

CRT     cathode-raytube

C SA    Command Switch Assembly

DCO     digitally controlled oscillator

DEC     declination

DIS     D i g i t a l I n s t r u m e n t a t i o n Assembly

 OR
D D     Digital Original Data                Record

DRA     D i g i t a l Recorder Assembly

DRG     Data RecorderGenerator.

D/S     data set
                                                     ,-.
DST     Data System T e r m i n a l Assembly

ECS     e r r o r c o r r e c t i n g and s w i t c h i n g

ESA     Exciter Switch           Assembly

EXC     E x c i t e r Assembly

EXT     external



                                                6- 1
    FDX     f l duplex (two-way)
            u l

    FMTR    formatter

    FTS     FederalTelecoqunications                           System

    GF
     C      Ground Communications F a c i l i t y

    GDSCC   Goldstone DeepSpace                        Communications Complex

    H A
     G      high-gain antenna

    HOST    HOST software program

    HSD     high-speed data

    HSDL    high-speed data               line

    IF      i n t e r m e d i a t ef r e q u e n c y

    I/O     input/output

    JPL     Jet Propulsion Laboratory

    KB      keyboard

    LGA     low-gain antenna

    MAG     magnetic

    MA
     C      Microwave Control Assembly

    MA
     D      M e t r i c D a t a Assembly

    MET     meteorological

    MMR     M u l t i m i s s i o n Open-Loop Receiver Assembly

    MON     Monitor and Control                   System

    NB      narrow band

    NC
    O       Network Operations Chief

    OA
     D      O c c u l t a t i o n D a t a Assembly

    OLR     Open-Loop Receiver Assembly
I
    O s
     P      operations

    PPR     Pre- and Postdetection Recording                        Subsystem

    PRA     Planetary Ranging                 Assembly


                                                         6-2
PRDX      predicts

RA        rightascension

RCVR      receiver

 D
R A       Ranging Demodulator              Assembly

SIC       spacecraft

SDA       Subcarrier Demodulator                Assembly

SI A      star switch interface adapter

SMC       S t a t i o n M o n i t o r and C o n t r o l Subsystem

SD
 P        S-Band P o l a r i z a t i o n D i v e r s i t y

S SA      Symbol Synchronizer Assembly

ssc       StarSwitchController

SSI       SpectralSignalIndicator

STA       Stimulus Assembly

S/W IiD   software block decoder

SN
 YC       synchronization

TODR      temporary o r i g i n a l d a t a r e c o r d

TPA       Telemetry Processor              Assembly

TRS       transmit/receive selector

T T
 WA       traveling-wavetubeamplifier

TX        transmitter

TXR       T r a n s m i t t e r Subsystem

uwv       Antenna llicrowave             Subsystem

VOCA      Voice CommunicationsAssembly

VK LDR    Viking Lander

WB        wideband

WBDL      widebanddata            line




                                                   6-3
                                                   ACKNOWLEDGMENT


          The V i k i n g L a n d e r M o n i t o r M i s s i o n    depended f o r i t s s u c c e s s f u l d a t a r e t u r n
upon t h e i n d i v i d u a l e f f o r t s o f a s m a l l number o f p e o p l e i n and a s s o c i a t e d w i t h ,
theNetwork.               Some o f thesepersons made s u b s t a n t i a l c o n t r i b u t i o n s t o t h i s r e p o r t
by f u r n i s h i n gd a t a ,r e p o r t s ,      o r o p i n i o n st ot h ea u t h o r .   I n t h i sr e g a r d ,t h e
c o n t r i b u t i o n s o f P. Eshe, S. LaVoie,                  A. B r i t t i n g , Jr., J . C . Nash, and J.P. B r e n k l e
a r e g r a t e f u l l y acknowledged.




                                                             7-1
                                                                    REFERENCES


 - .
1 1 Mudgway, D.J., and M.R. T r a x l e r ,T r a c k i n ga n dD a t a   SystemsSupport                forthe
     V i k i n g 1975 M i s s i o nt o Mars: Volume I P r e l a u n c h l a n n i n g , m p l e m e n t a t i o n ,
                                                          .            P              I
           a n dT e s t i n g ,T e c h n i c a l   Memorandum 33-783.                        J e tP r o p u l s i o nL a b o r a t o r y ,
           Pasadena, C a l i f . , Jan. 1977.    15,

1-2.       Mudgway, D.J.,         and M.R. T r a x l e r ,T r a c k i n ga n dD a t a         SystemsSupport f o r t h e
           V i k i n g 1975 M i s s i o n t o Mars:                     1
                                                       Volume 1 . L a u n c hT h r o u g hL a n d i n go fV i k i n g                                    1,
           T e c h n i c a l Memorandum 33-783.        J e tP r o p u l s i o nL a b o r a t o r y , Pasadena, C a l i f . ,
           March 15, 1977.

1-3.       Mudgway, D.J.,              T r a c k i n ga n dD a t aS y s t e m sS u p p o r tf o rt h eV i k i n g1 9 7 5M i s s i o n
           t o Mars:   Volume                1.                    O
                                           1 1 Planetary perations, echnical         T                          Memorandum 33-783.
           J e tP r o p u l s i o nL a b o r a t o r y ,    Pasadena, C a l i f . ,S e p t .              ,
                                                                                                       1 1977.

1-4.       Mudgway, D.J.,   T r a c k i n ga n dD a t aS y s t e m sS u p p o r tf o rt h eV i k i n g       1975 M i s s i o n
           t o Mars:   Volume I V .                    M         O
                                          Extended ission perations, echnical      T                      Memorandum 33-
           783.      P           L
                  Jet ropulsion aboratory,                 Pasadena, C a l i f . , Dec. 15,            1978.

1-5        L a r k i n , W.E.,   T e l e c o m m u n i c a t i o n sa n dD a t aA c q u i s i t i o nS y s t e m sS u p p o r tf o r
           t h e V i k i n g 1975 M i s s i o n t o Mars, 1 June1978 t o 30 A p r i l 1980, JPL P u b l i c a -
           t i o n 82-18.      J e tP r o p u l s i o nL a b o r a t o r y ,    Pasadena, C a l i f . , A p r i l           15, 1982.

2-1    a   Snyder, C.W.,            and N. Evans, "The F i n a l Phases o f t h e V i k i n g M i s s i o n t o                                      Mars,"
           Icarus, Vol.            45, pp. 2-24, 1981.

3-1.       Manager,Frequency                 Management Programs, OSTDS, Wa'shington, D.C., "Waiver
           o f N a t i o n a l a n d NASA D i r e c t i v e s R e q u i r i n g O n / O f f Telecommand C a p a b i l i t y f o r
           Remaining Viking Lander," L e t t e r t o D i r e c t o r , SpectrumPlansandPolPcy,
           N a t i o n a lT e l e c o m m u n i c a t i o n sa n dI n f o r m a t i o nA d m i n i s t r a t i o n ,W a s h i n g t o n , D.C.,
           Jan. 20, 1982.

3-2.       D i r e c t o r ,S p e c t r u mP l a n s       and P O l i c y , N a t i o n a l T e l e c o m m u n i c a t i o n s a n d I n f o r -
           m a t i o nA d m i n i s t r a t i o n ,W a s h i n g t o n ,   D.C.,        "Concurrence With Request f o r
           Waiver," L e t t e r t o P. Struba, Code TN-OSTDS, Jan. 20, 1982.

4-1.       Reasenberg, R.D., 1.1. Shapiro, P.E. MacNeil,                                           and                                       and
                                                                                                                 R.B. G o l d s t e i n (MIT),
           J.C. B r e i d e n t h a l , J.P. B r e n k l e , D . I . Gain, T.M. Kaufman, T.A. Komarek, and
           A . I .Z y g i e l b a u m( J P L ) ," V i k i n gR e l a t i v i t yE x p e r i m e n t :V e r i f i c a t i o no f
           S i g n a l R e t a r d a t i o n by S o l a r Gravity," A s t r o . J., V o l . 234, Nos. L219 - L221,
           Dec. 15, 1979.

4-2.                  . .    ,
           Shapiro, I IR.D. Reasenberg, P.E. MacNeil,          and        R.B. Goldstein             (MIT),   and
                       D.L.
           J.P. Brenkle,  Gain,                           A.I.
                                           T. Komarek,,and Zygielbaum       (JPL),    and                     W.F.
           Cuddihy and W.H. M i c h a e l , Jr., (LRC), "The V i k i n g R e l a t i v i t y E x p e r i m e n t , "
           J. Geo. Res.. V o l . 82, No. 28, Sept. 30, 1977.




                                                                            8-1
   APPENDIX A


SAMPLE NEWS RELEASE




       A- 1
 O F F I C E OF PUBLIC INFORMATION
 JET PROPULSION      LABORATORY
 CALIFORNIA I N S T I T U T E OF TECHNOLOGY
 N A T I O N A L AERONAUTICS AND SPACE A D M I N I S T R A T I O N
 PASADENA, CALIF. PHONE ( 2 1 3 ) 3 5 4 - 5 0 1 1


 FOR I M M E D I A T E RELEASE


                     A f t e r more t h a nf o u ry e a r se x p l o r i n g               Mars, NASA's

 V i k i n gO r b i t e r      1 hasalmostreachedthe                            end o f i t s m i s s i o n .

                                         used
                     The o r b i t e r has                       almost a l l i t s a t t i t u d e - c o n t r o l

gas,       t h a t keeps i t s s o l a r p a n e l s p o i n t e d t o t h e                 Sun and t h e an-

tenna aimed a t E a r t h .                When thegas                 i s exhausted         --   p r o b a b l ya b o u t

July 23         --     controllersatJetPropulsionLaboratory                                          i
                                                                                                     l
                                                                                                     l
                                                                                                    w send

commands t o t u r n o f f V i k i n g O r b i t e r                     1 t o end i t s l o n g        and p r o d u c t i v e

mission.

                     Meanwhile,VikingLander                            1 i s programmed t o o p e r a t e             un-

a t t e n d e do n       Mars i n t o 1 9 9 0 , perhaps t o beextended                            i n t o 1994.

                     D u r i n gt h em o s tr e c e n t            phase o f V i k i n g ' s m i s s i o n t h e

o r b i t e r hastakenabout                   3 0 p i c t u r e s a day o f a r e g i o n s o u t h w e s t                  of

Olympus Mons and t h e t h r e ev o l c a n o e so nt h eT h a r s i sR i d g e ,a na r e a

o fp a r t i c u l a ri n t e r e s tf o ri t sl a r g e ,r i v e r - l i k ec h a n n e l s .T h a t

          l
          l
          i
sequence wc o n t i n u et h r o u g hJ u l y                           12.

                     Project officials pian                        a f u l l program f o r O r b i t e r 1 ' s

f i n a l days. How much o f t h e programcanbecompleted                                              l
                                                                                                      i
                                                                                                      l
                                                                                                     w depend

o nt h e     amount o f a t t i t u d e - c o n t r o l gasremaining.Here                              i s a timeline

o f e v e n t st h a ta r ep r o p o s e dt o                be c a r r i e d o u t      i f t h e o r b i t e r con-

tinues to            be c o o p e r a t i v e :

                     J u l y 138 14:                                 l
                                                                     i
                                                                     l
                                            The s p a c e c r a f t wt a k e a s e r i e s o f h i g h -

r e s o l u t i o np h o t o s     o f t h e summit c a l d e r a o f Olympus Mons. These

s h o u l d be t h e h i g h e s t - r e s o l u t i o n e v e r o b t a i n e d           of thecalderaof

thesolarsystem'slargest                            known volcano.

                                                          A- 2         (more )
                   J u l y 1 5 t h r o u g h 1 8 : The s p a c e c r a f t w p e r f o r mt h r e e
                                                                            i
                                                                            l

c o n t r o l l e db u r n s    o f i t sr o c k e te n g i n e s .           Those b u r n s a r e p a r t o f

a s e r i e so fe n g i n e e r i n gt e s t st op r o v i d ed a t at h a t                       l
                                                                                                   i
                                                                                                  w benefit

f u t u r e s p a c em i s s i o n s .      One e f f e c t o f t h e b u r n s             l
                                                                                            i
                                                                                           w be t o change

t h es p a c e c r a f t ' so r b i tf r o mi t sp r e s e n t                370 kilometers ( 2 3 0 m i l e s )

p e r i a p s i s and 3 4 , 0 0 0 k i l o m e t e r s ( 2 1 , 1 2 7          m i l e s )a p o a p s i st o       350

k i l o m e t e r s ( 2 2 0 m i l e s )p e r i a p s i s          and 5 6 , 0 0 0   kilometers (34,800

m i l e s )a p o a p s i s .    The new o r b i t w s a t i s f y t h e c o n d i t i o n ,
                                                   l
                                                   l
                                                   i                                                             i n ac-

cordance w i t h p l a n e t a r y - q u a r a n t i n e p r o v i s i o n s ,             o f n o ti m p a c t i n g ,

and t h e r e b y not c o n t a m i n a t i n g ,t h ep l a n e tb e f o r et h ey e a r                       2019.

                   J u l y 2 0 t o 23: A d d i t i o n a le n g i n e e r i n gt e s t s                l
                                                                                                        i
                                                                                                        l con-
                                                                                                       w be

d u c t e d ,p r i n c i p a l l yo nt h er a d i o                     and
                                                                  system,               the final orbit               wi
                                                                                                                       l
                                                                                                                       l

be d e t e r m i n e d .

                   Currentextrapolation                         o f t h es u p p l y     andusage            rate of

a t t i t u d e - c o n t r o lg a si n d i c a t e s          July 2 3 i s t h e a p p r o x i m a t e d a t e           of

depletion,           but f l i g h t c o n t r o l l e r s         s a yt h e r e      i s p r o b a b l y a one-week

u n c e r t a i n t y i-n t h a t d a t e ,      so t h e o r b i t e r c o u l d r u n o u t            o f gasas

earlyas          J u l y 1 6 o r as l a t e a s J u l y 3 0 .

                   I f i should turn o u t t h a t t h e r e i s s t i l l
                       t                                                                            gasr em a i ni ng,

t h e na b o u tJ u l y                             i
                                                    l
                               2 7 O r b i t e r 1 w make a f i n a l h i g h - a l t i t u d e g l o b a l

surveyofthevisibleportion                                 o f t h eM a r sd i s k          --    25 p i c t u r e s

thr oug he a c h          of threefilters,for                        a t o t a l o f 7 5 frames.

                   When t h eg a s          i s exhausted,              the orbiter'sradiotransmit-

t e r wbe commanded o f f f o r t h e l a s t t i m e ,
       l
       i
       l                                                                                and t h es p a c e c r a f t

 l
 i
wcontinuesilentlyorbiting                                       Mars f o r many decades.

                   V i k i n g 1 was l aunched t o Mars Aug.                            20,     1 9 7 5 , and a r r i v e d

June 198 1976. V i k i n gL a n d e r                    1 touched down o nt h eM a r t i a ns u r f a c e
                                                        A- 3
July 20,         1976,      w i t h a 90-day m i s s i o ne x p e c t a t i o n .T h a tm i s s i o n                 com-

pleted,         i has now o b s e r v e dt h ep l a n e tf o r
                t                                                                 more thantwo             f u l l Mars

years      --    f o u rE a r t hy e a r so nJ u l y             20.

                  As .longas           i s u r v i v e s ,V i k i n gL a n d e r
                                       t                                                   1 w c o n t i n u et o
                                                                                              i
                                                                                              l
                                                                                              l

c o l l e c tp h o t o s    and w e a t h e rd a t af r o mt h eM a r t i a ns u r f a c e                 and,     on

command f r o mE a r t h ,t r a n s m i t              them o na p p r o x i m a t e l y         a w e e k l yb a s i s .

                  VikingOrbiter               2 ran out of attitude-control                             gas and

was
  commanded                offJuly        24,     1978. V i k i n gL a n d e r           2 was t u r n e d o f f

afteritslastrelaytransmission                                    A p r i l 1 , 1980.
                                                                            1

                  The V i k i n g P r o j e c t        --     t o d a yw i t hf e w e rt h a n        3 0 people

engaged i n f l i g h t o p e r a t i o n s            and s c i e n c ed a t ap r o c e s s i n g         --    i s man-

aged f o r NASA's O f f i c e o f Space S c i e n c eb yJ e tP r o p u l s i o nL a b o r a t o r y .



                                                            #####

#940/7/9/80/DB




                                                       A- 4
                   APPENDIX B



VIKING LANDER MISSION SUPPORT EXTENSION REQUEST

               V - )
       LANDER ( L1 MONITORING MISSION

    JULY 20,1979         DECEMBER
                   THROUGH          29,1990




                      B-1
OBJECTIVES

1.     O b t a i n S-band r a n g i n gd a t af r o mt h es u r f a c e o f Mars p e r i o d i c a l l yo v e r                       a
       l o n g t i m e span f o r t h ec o n d u c t o f RadioScience.

2.     Obtain eteorology ndmaging ata rom he urface
                 m                 a i         d      f     t s                                    o f Mars p e r i o d i c a l l y
       o v e r a l o n gt i m es p a nt om o n i t o ra n dd i s s e m i n a t ei n f o r m a t i o nr e l a t i v e         to
       a n y s i g n i f i c a n t changes w i t h time.

      REQUIREMENTS
SUPPORT




        1.      R e t a i ne x i s t i n g                 t               a
                                             DSS l a n d e r e l e m e t r y n d        command s o f t w a r ec a p a b i l i t y .

       2.       A t l e a s t two
                                64-meter
                                       passes                     o f . 3h o u r sd u r a t i o np e rm o n t ht h r o u g h              1980.

       3.       A t l e a s t one 64-meter pass o f 3 h o u r sd u r a t i o np e rm o n t ht h r o u g h                             1981.

       4.       Subsequent
                         years                -   to e egotiated n
                                                    b n         o                            b
                                                                                     a yearly asis.

-
MCCC

        1.                 t
                S u p p o rr e q u i r e m e n t s o n t a i n e d
                                                 c                 within t h e r b i t e r e q u i r e m e n t s
                                                                               o                                                  until
                2/1/80.         No MCCC dependency o rr e q u i r e m e n t st h e r e a f t e r .

          INTERFACE
PROJECT/DSN

1.      m ep r o j e c ts h a l lp r o v i d e       a p e r s o nt oa c ta s         a f o c a lp o i n tf o ra l - 1l a n d e r /
       -DSN i n t e r a c t i o n s .

2.     The p r o j e c ti n p u t st ot h e             i            s                  p
                                            DSN s h a l l n c l u d e c h e d u l i n g , r e d i c t i o n s ,
       sequences, commands and o p e r a t i o n a l d i r e c t i o n during passes.

3.     The DSN s h a l lp r o v i d el a n d e r             and
                                                          IDRs               p       t t   p
                                                                         data ackages o his erson.




R. S. W a t k i n s                                                         Thomas A. Mufch
V i k i n g P r o j e c t Manager                                           A s s o c i a t eA d m i n i s t r a t o rf o r
                                                                            SpaceScience




~Zuce Nurray, Director "                                                    W. C. Schneider
JetPropulsionLaboratory                                                     AssociateAdministrator for
                                                                            Space TrackingandDataSystem6



                                                                  B-2
                                                      APPENDIX C*




                  VIKING LANDERMONITOR              MISSION DIRECT-LINK REQUEST SUMMARY




*The i n f o r m a t i o n i n t h i s a p p e n d i x was t a k e n f r o m I n t e r o f f i c e Memorandum 3394-82-
 1 2 2 f r o m P. Eshe t o G. G i a n o p u l o u s , " V i k i n g L a n d e r M o n i t o r M i s s i o n D i r e c t Link,"
 J e tP r o p u l s i o nL a b o r a t o r y , Pasadena, C a l i f . ,O c t .    7, 1982.



                                                            c- 1
First year of the             VLMM August 1 3 ' t o December 28, 1980:

       19 t o t a l passes a v a i l a b l e

         9passesscheduled

         9passesunable               t o schedule(informationnotavailable)

         1 pass was o u t o f s t a t i o n v i e w p e r i o d

       Good low-rate     high-rate
                    and/or            8
                                  data: passes

       Good ranging
                  data:                   7 passes

       Bad low-rate     high-rate
                   and/or        data:                                none

       Bad r a n g i n gd a t a :       1 rangingpassbad                due t ol o c k e ds i d e b a n d

       Lostdirect           link:       1 - badpass due t o d i g i t a l l y c o n t r o l l e d o s c i l l a t o r          (DCO)
                                        sweep problem


Second y e a r o f t h e       VLMM January 4 t o December
                                                         27,                       1981:

       48 t o t a l p a s s e s a v a i l a b l e

       31passesscheduled

       1 7 passes
                unable              t o schedule.         Reasons:

               4 passes given            up t o P i o n e e r

               7 passes given            up t o Voyager

               1pass given up to Helios

               3passesgivenup                  due t o S t a t i o n 1 4 b e i n g down

               2 passes were out               o f station viewperiod

       Good low-rateand/orhigh-ratedata:                               22 good passes o f l o w - r a t e and h i g h -
                                                                       rate data

                                                                         1 pass good h i g h - r a t e d a t a

                         d
       Good r a n g i n g a t a :        23 passes

       Bad low-rateand/orhigh-ratedata:                               1 pass no low-ratedata;nosync

                                                                      1 wrong TPA c o n f i g u r a t i o n ; l o s t b a t t e r y
                                                                      data

      Bad r a n g i n gd a t a :        1 pass PRA
                                                 RED


                                                                c-2
    Lost direct      link:

    1 - Sun-Earth-probe            (SEP) angle 1.2 deg

    1 - transmittertripped o f f
    1 - wrong command sent

    2 - D O sweep problem
         C

    2 - DSS 14 was scheduled; s t a t i o n was
                                              down


Thirdyear    o f t h e VLMM January 4 t o December 28, 1982:

    48 t o t a l passes a v a i l a b l e

    41passesscheduled      at this time  (Dec. 12 t o Dec. 28 have n o t beenscheduled
    yet).  To t h i s day, we have  had 36 passes a v a i l a b l e .

      3 passes
             unable           t o schedule.         Reasons:

            1 pass given up         t o r a d i o astronomy f o r A u s t r a l i a n e x p e r i m e n t

            1 pass out       o f station viewperiod

            1 passunable t o schedule DSS 63 due t o g e a r b o xr e p a i r .T r i e d                      for
            DSS 6 1 i n s t e a d o f DSS 63, but Voyagerneeded DSS 61.

     Good low-rateand/orhigh-ratedata:                         32 passes

                                                                  2 passes o f good l o w - r a t e d a t a

     Good ranging:        29 passes

     Bad low-rateand/orhigh-ratedata:                         1   -   u n a b l et ol o c k u po nh i g hr a t ed a t a ,
                                                                      probably due t o b e i n g o n l y one way.

                                                              1 - no high-rate data            due t o o n l y
                                                                  34-m s t a t i o n a v a i l a b l e

     Bad ranging:        1   -   unknown

                         1 - PRA declared RED

                         1   - wrong     tuning

                         1- downlink only

     Lostdirect       link:       1 pass DSS-14 r a d i a lb e a r i n gp r o b l e m




                                                        c-3
                                                           APPENDIXD*


                    VIKING LANDERMONITOR                 MISSIONDIRECT-LINK                 REQUEST DETAIL




"The i n f o r m a t i o n i n t h i s a p p e n d i x was t a k e n f r o m I n t e r o f f i c e                  Memorandum 3394-82-
 1 2 2 f r o m P.     Eshe         t o G. G i a n o p u l o u s , " V i k i n g L a n d e r M o n i t o r M i s s i o n D i r e c t Link,"
 J e tP r o p u l s i o nL a b o r a t o r y ,P a s a d e n a ,      C a l i f . , O c t . 7, 1 9 8 2 .



                                                                  D- 1
                             Day
                              of    Sol
Year Date Year                      No.     DSS          Scheduled             Comments

             3
        8 /1 9 8 0           226    1445    12             Yes       Good pass

                     8/20    233    1452                   No

                     8/28    241    1460                   No

                     915     249    1468    63             Yes       Good pass

                     9/12    256    1475                   No

                     9/20    264    1482    42             Yes       Good pass

                     9/27    271    1489                   No

                     1015    279    1497    63             Yes       Good pass

                     10113   287    1505                   No

                     10/20   294    1512    14             Yes       No good
                                                                     DCO sweep problem

                     10128   302    1519                   No

                     1114    309    1526    43             Yes       Good pass
                                                                      :O l a t e
                                                                     1l

                     11/12   317    15 34                  No

                     11/20   325    1542                   No        No v i e w p e r i o d

                     11/27   332    1549    14             Yes       Good pass
                                                                     00:35 l a t e

                     1215    340    1556                   No

                     12/12   34 7   1563    43             Yes       LR/HR d a t a OK.        No
                                                                     rangingdatalockedon
                                                                     sideband

                     12/20   355    1571    63             Yes       Good pass

                     12/28   363    15 79                  No

        1 /149 8 1           004    1586    43             Yes       Wrong TPA c o n f i g . ; l o s t
                                                                     b a t t e r yd a t a ; good
                                                                     ranging



                                                  D- 2
                                    ~~~~          ~    ~




                             Day
                              of    Sol
Year Date Year                      No.      DSS           Scheduled              Comments

        1 /1 9 3 1
             2               012    1593     43              No        Gave up f o r PN-12

                     1/19    019    1600     43              Yes       Good pass

                     1/27    027    1608     63              Yes       Good pass

                     214     035    1616     14              No        Gave up f o r PN-12

                     2/11    04 2   1623     14              Yes       Good pass

                     2 119   050    1630     43               Yes      Good LR/HR d a t e ; no
                                                                                        RED)
                                                                       r a n g i n g (PRA

                     2/26    05 7   1637                     No        No v i e w p e r i o d

                     3 16    065    1645     63               Yes      Good pass

                     3/14    073    1653     14               No       DSS-14 maintenance

                     3/21    080    1660     14               Yes      SEP 2.6 deg; a c c e p t a b l e
                                                                       LR/HR d a t a ; n o r a n g i n g

                     3/29    088    166 7    43               Yes      SEP 1 . 2 deg; n o LR/HR
                                                                       Data

                             095    1674     63               Yes      SEP 0.8 deg; No d a t a .
                                                                       H i g h - p o w e rt r a n s m i t t e r
                                                                       tripped off

                     4/13    103    1682     63               No       Gave up f o r P i o n e e r            12

                     4/21     1
                             11     1690     14               No       Gave up f o r P i o n e e r 1 2

                     4/28    118'   1697     43               Yes      Good pass
                                                                       One r a n g k n g p o i n t

                     516     126    1704     43               No       Gave up f o r Voyager 2

                     5/13    133    1711     63               Yes      Good pass

                     5/21    141    1719     63               Yes      Good pass

                     5/29    149    1727     14               Yes      Good pass

                     615     156    1 7 34   43               Yes      Good pass

                     6/13    164    1741                      No       No v i e w p e r i o d




                                                      D- 3
                           Day
                            of   Sol
Year Date Year                   No.    DSS   Scheduled            Comments

          19
        6/20 81            171   1746   63      Yes       Good pass;gaveup

                  6/28     179   1756   63      No        ForVoyager          2

                  7/6      187   1764   14      Yes       Good pass

                  7/13     194   1771   43      Yes       Good pass

                  7/21     202   1778   63      Yes       Good pass

                  7/28     209   1785   63      No        Gave up f o r Voyager

                  815      217   1793   63      No        Gave up f o r Voyager

                  8/13     225   1801   14      No        Gave up f o r Voyager

                  8/20     232   1808   43      No        Gave up f o r Voyager

                  8/28     240   1815   63      Yes       Good pass

                  914      247   1822   63      No        Gave up f o r Voyager

                  9/12     255   1830   14      Yes       DSS 1 4 down

                  9/20     263   1838   14      Yes       DSS 1 4 down

                  9/27     270   1845   43      Yes       Good pass

                  1015     278   1852   63      Yes       Good pass

                  10112    285   1859   63      Yes       Good h i g h r a t e and
                                                          r a n g i n g ; no l o w r a t e

                  10/20    293   1867   14      No        DSS-14     g e a r b o xr e p a i r

                  1/28     301   1875   43      Yes       No good
                                                          Wrong command s e n t

                  1114     308   1852   43      Yes       Good pass

                  11/12    316   1889   63      Yes       No good; D O problem
                                                                    C

                  11/19    323   1896   63      Yes       Good pass

                  11/27    331   1904   14      No        DSS 1 4 down

                  12 /05   339   1912   43      Yes       Good pass
                             Day
                              of   Sol
Year Date Year                     No.    DSS          Scheduled            Comments

            /13
        1 21 9 8 1           347   1919   63             Yes       Good pass

                     12/20   354   1926   63             No        Gave up f o r H e l i o s

                     12/27   361   1933   14             Yes       No good; DCO problem

           4
        1 /1 9 8 2           004   1941   43             Yes       Good pass

                     1/12    012   1949   43             Yes       Good low- and h i g h - r a t e
                                                                   data;rangingno      good

                     1/20    020   1956   63             Yes       Good pass

                     1/27    027   1963   63             Yes       Good pass      I




                     213     034   1970   14             Yes       Good pass

                     2/11    042   1975   43             Yes       Good pass

                     2/19    050   1936   43             Yes       Good pass

                     2/27    058   1993   63             Yes       Good pass

                     316     065   2000   14             Yes       Good l o w - and h i g h - r a t e
                                                                   d a t a ;r a n g i n g no good

                     3/13    072   2007   14             Yes       Good pass

                     3/21    080   2015   42             Yes       Good pass

                     3/29    088   2023   63             Yes       Good pass

                     416     096   2030   14             Yes                          l
                                                                   No good; r a d i a b e a r i n g     ~r

                                                                   problem

                     4/13    103   2037   14             Yes       Good pass          ~ ' L Y ?




                     4/20    110   2044   43             No        Gave up f o r Radio
                                                                   Astronomy A u s t r a l i a n
                                                                   Experiment

                     4/28    118   2052   63             Yes       Good pass                L.



                     516     126   2060   63             Yes       Good pass                bc



                     5/14    134   2067   14             Yes       Good pass           L/




                                                D- 5
                           Day
                            of      Sol
Year Date Year                      No.     DSS          Scheduled                        Comments
                                                                                                                                 L
        5/1982
          21               141      2074    43             Yes       Good l o w - a n d h i g h - r a t e
                                                                     d a t a ;r a n g i n gn o     good;
                                                                     commanding no good

      43 2081 148 5/28                                     ‘Yes      Good l o w - a n d h i g h - r a t e
                                                                     d a t a ;r a n g i n gn o    good

                  615      1 56   63 2089                  ‘Yes      Good pass                    LJ‘


                  6/13     164    12 2097                  ‘Yes      Good pass                   L,



                  6/21     172    43 2104                  ‘Yes      Good pass               t



                  6/28     179    43 2111                  Yes       Good pass                   t.



                  715      186    63 2118                  ‘Yes                      a
                                                                     No u p l i n k v a i l a b l e ;                       r/
                                                                     n or a n g i n ga v a i l a b l e ;
                                                                     l o s t h i g h - r a t ed a t a ,
                                                                     l o w - r a t eo k

                  7/13     194      2126    63             Yes       Good pass                   L/



                  7/21     202      2134    12             Yes       Good pass

                  7/29     210      2141    43             Yes       Good pass                   r/


                  8 15     217      2148    43             Yes       Good pass                fl


                  8/12     224      2155    63             Yes       Good pass

                  8/20     232      2163    63             ’le s     Good pass                -
                  8/28     240      2171    14             Ifes      Good pass; two r a n g i q g
                                                                     points     J



                  915      248      2175    43             Yes       Good pass /

                  9/12     255      2185    43             Yes       Good pass .                      bc   L”
                                                                                                             \
                                                                                                                 :. ,I
                                                                                                                   .
                                                                                                                        v




                  9/19     262      2192    61             Yes       Good pass;no                          HR d a t a

                  9/27     270      2200                   No        No v i e w p e r i o d                ?-


                  10/5     278      2208    14             Yes
                                                                       ..        \
                                                                                 \




                 286 113
                  10                2215    43             Yes               ‘. ,
                                                                         ,   ,       L-




                                                  D- 6
                                   Day
                                    of   Sol
Year Date Year                           No.    DSS      Scheduled                         Comments

2222 203 1982
       10120                                    43           Yes         ,.
                                                                             + .
                                                                                 ./. .

          2 2 2 9 3 0 01 0 / 2 7                61           No    I
                                                                   -   Unable t o have DSS 6 3
                                                                       due t o g e a r b o x r e p a i r ;
                                                                                                                 "
                                                                                                                 !
                                                                       VGR needed DSS 6 1 f o r
                                                                       test
                                                                         1 .


                       11/4        308   2237   14           Yes
                                                                         I
                                                                         1   ~. ,.
                                                                              '



                       11/12       316   2245   14           Yes             <         I




                       11/20       324   2252   43           Yes

                       11/27       331   2259   43           Yes                                      'I
                                                                                                      .    , I




                       1214        338   2266   63           Yes

                       12/12       346   2274   14

                       12/20       354   2282   14

                       12/28       362   2289   43




                                                      D- 7
                 APPENDIXE


AN EXAMPLE OF VIKING LANDER
                          SEQUENCE   OF EVENTS




                     E- 1
JPL001A
  ; ; :4   iJEE JZED           OUTGOING MESSAGE

02/00012
F J NASH/R hEVAREZ
  M
TO ANBE/STADIR/43 OPS
JOCC/NOC~TRKCHF/NATCMD/NATRK/NATEL
I N F O JZED/PAG
DLD W JENSEN/G REED/E BURKE/A BERMAN/D MUDGWAY/K LUDWIG/R GfLLETTE/
P ESHE/A BRITTING/GGIANOPULOS/J  BRENKLE/E HAMPTON/R HOLLINCSWORTH/
J HODDER/S BENEDICT/T BOREHAM/COMM
                                 CONTROL

SUBJECT: V I K I N G LANDER SOE FOR DSS-43, SOL-2178 DOY-248
1. ON DOY 248 DSS-43 WILL BE SUPPORTING A V I K I N G LANDER RADIO                   SCIENCE
    R A t i G I N C PASS. PROJECT HAS REQUESTED THAT BATTERY CONDITIONING
    COMMANDS BE        TRANSMITTED    DURING THIS TRACKING PASS. THREE
    TRANSMISSkONZ WILL BE         REQUIRED.         THE FIRST   TRANSMISSION WILL BE THE
    DOW~LINK           ON COMMANDS, THE SECOND T A S I SO
                                                       R N MS I N       WILL BE THE BATTERY
    CONDITIONIl4G,,COMMANDS, AKD THE THIRD             TRANSMISSION        WILL BE THE
    DOWNLINK "ON COMMANDS FOR THE TRACKING                 PASS      SCHEDULED OVER DSS-43
    ON DOY 255.
    I T I$       REQUIRED THAT 9 LANDER ( S / C - 2 6 ) COMMANDS BE MANUALLY LOADED
    INTO THE MANUAL BUFFER DURING              PTP.
2 . UPLINK TRANSMITTER POWER WILL BE 10KW.
3. DURING       THE     FIRST'HOUR OF THE 1 1 / 2 HOUR PTP, CONFIGURE          THE    STATION
    FOR LAWDER       SUPPORT.    CONFIGURE ONE TPA FOR LANDER          SUPPORT      (CH-1,  IK
    AND CH-2, 8.33 HSD).        USE     SOFTWARE    BLOCK      DECODING FOR LAhDER l K
    CODED DATA. ENSURE THAT THE S S A TO B EU T I L I Z E D I N SUPPORT OF THE
    I K CODED DATA I S SET WITH A THKESHOLD OF 0.0 DB.
4. CONFIGURE THE PRIME CPA FOR LANDER                COMMANDIKG.       MANUAL COMMANDS WILL
    ENTERED FOR THE FIRST ANC SECOND TRANSMISSION                   DURING    THE PTP AND
    AFTER NATCMD HAS VALIDATED THE COMMANDS SYSTEM PEil SOE. THE THIRD
    SET O COMMANDS WILL BE LOADED INTO THE
               F                                           MANUAL      BUFFETi DURING THE
    LAST HOUR OF THE TRACKING PASS,
5 . DURING PTP  THE         PERFORM R A K G I N G PRE-CALS FOR LAhiDER.
    COMP:           0 6
    TO:             3E
    T1:             90
    T2 :             9
    T3 :            60
    CARRIER      SUPRESSION:     9DB
6 . SEQUENCE OF EVENTS FOR LANDER SUPPORT
    02:25:00 DSS-43 CONFIGURE S T A T I O N FOR LANDER             SUPPORT
    03:10:00 DSS-43 TURN COMMAND SYSTEM OVER TO                   NATCMD   FOR VALIDATION
    03:20:00 DSS-43 AFTER COMMAND VALIDATION, RETURN TO MANUAL AND
                             ENTER THE COMMANDS I N T O TEE FOLLOWING OhDER.

    MOUDLE    MSG NBR      II
                          BT TM E                 PATTERN
      1        I           248:04:23:00       5 5 5 5 5 5 5 5 5 5 5        5 5 5 5 E 2 5
             2             NONTIMED           6 8 2 0 1 ' 7 0 1 6 F 4       5 0 0 B D 8
             3             NONTIMED.          5 F 4 4 0 0 B 9 5 F A        C E 8 C A 8
   MODULE MSG NBR          II
                          BTTM E                  PATTERN
     42
    248:04:38:00.                             5 5 5 5 5 5 5 5 5 5 5        5 5 5 5 E 2 5
             5             NONTIMED           6 8 2 0 1 D 7 2 7 D 3         9 0 0 D 9 8
             6             NONTIMED           7 1 E A Z B C 6 B 4 D        D 0 B F A 8
             7             NONTIMED           C Z D C 0 0 E Z F 4 D        D B a A 2 8
             8             NONTIMED           0 0 0 @ 0 0 D E C 9 B        9 € 3 a 9 5 8
             9             NONTIMED           Z Z D C 0 D 1 9 1 4 B        E 0 9 0 6 8

MORE                                  e   n
                                      B- L
JPL003A
RR A N B E O C C Z E D
         J     J
DE JJPL 0038
02/0001z

P A G E TWO
     @3:35:00                3         IM          L R            C           S           B
                   D S S - 4 R E M A I NN A N U A A N D E T U R N O M M A N D Y S T E M A C K
                                   OVER O AT
                                           TN                CMD FOR MODULES 1 AND 2 V A L I D A T I O N .
     @3:36:00                  R         L          L         A V
                   N A T C M D E C A LM A N U AB U F F E R N D A L I D A T E                        COMMAND B I T
                                   PATTERNS.
     03:51:00                3
                   DSS-4AFTER ATCMD N                         HAS V A L I D A T E D COMMAND BJT P A T T E R N S , ,
                                              TO
                                   RETURN REMOTE.
     03:52:@0                  V
                   NATCMD ERIFY ORRECT  C                                                      T   D
                                                                  COMMAND T R A N S M I T I M E I S P L A Y E D      ON
                                   FORMAT 301.
     03:55:00      D S S - 4S T A R T
                             3                  O L A N D E RR A C K
                                                  F             T           SOL-21'78
     04:01:00      D S S - 4T R A N S M I T T E R N
                             3                   O                (10KW) L A N D E F L A G / C - 2 6 , - B A N D
                                                                                        R S        S
                                   O N L Y , Z-WAY, B A D A T A , D            ROL I N THE MDA.
                                   MDA DATA R A T E S : 1 S A M P L E / 1 0 SEC. A T AOS                      TO LOS
                                   OF L A N D E R A S S .
                                                      P
     04:01:2?      DSS-43                  T                  S       AP S
                                   STARACQUISITION WEEP S ER WEEP ESSAGE.           M
     04:18:00      DSS-43  COMMAND       MODULATION                      ON
     04:19:08                3      D
                   D S S - 4S E N ID L E - 2 / A C T I V E               ON
     04:24:00                   C
                   NAT/DSS ONPIRM IRST       F                  COMMAND T R A N S M I S S I O N
     04:39:00                   C
                   NAT/DSS ONFIRM ECOND    S                      COMMAND T R A N S M I S S I O N
     04:48:00                 N        Y          G
                   T R K C OV E R I TB A N G I N P A R A M E T E R S
     04:41:@0      NATCMD FTER LL INE
                               A        A N                       ( 9 ) COMMANDS H A V E BEE^ T R A N S M I T T E D
                                         C                 ,         T I                    O
                                   A N D O K F I E M E DR E T U S N OD L E - l / A C T I V E F F .
    04:45:00       DSS-43          RANGING ON    MOD
    B4:49:58       DSS-43          T R A K S M I TF I R S TR A N G EA C Q U I S I T I O N
    @5:12:52       DSS-43                   S          F D
                                   START WEEP OR OWNLINK CQUISITION       A
    @5:14:22       DSS-43          AOS  (2-WAY)   S/C-26                               C
                                                                         LOW R A T E H A N N E L         8 1/3 UNCODED
    05:14:52       DSS-43          R E C I E V EF I R S TR A E G EA C Q U I S I T O N
    05:15:00                 3
                   D S S - 4R E T U R N                                        M
                                                  COMMAND S Y S T E M s T O A N U AM O D E L
    @5:16:00       DSS-43 LEAhC                 THE M A N U A L U F F E R
                                                                  B              AND E N T E R THE T H I R D SET OF
                                   COMMANDS I N THE FOLLOWING                    ORDER.

   MODULE         MSGI MN B R
                    T E                                    B I T PATTERN
     1             10         248:05:34:30                 5 5 5 5 5 5 5 5'5 5 5 5 5 5 5 E 2 5
                   11         NONTIMED                     6 8 2 0 1 ' 7 0 1 6 F 4 5 0 0 B D 8
                   12         WONTIMED                     5 F 4 4 0 0 B 9 5 F A C E 8 C A 8
    05:16:57 DSS-43           RANGING    MOD          OFF
    05:21:00 D S S - 4 3 E M A I N
                         R                  I N MANUAL           AND
                                                           MODE RETURN         COMMAND      SYSTEM
                              OVER TO     NATCMD           FOR M A N U A L BUFFER V A L I D A T I O N .
                           R       M           B         A V             C
    05322308 S A T C M D E C A L L A N U A L U F F E R N D A L I D A T E O M M A N D I TB
                              PATTEEN
                         3     N         H V
    05:27:00 D S S - 4 A F T E R A T C M D A S A L I D A T E D                     COMMAND B I T P A T T E R N ,
                              T R A N S F E i l MANUAL 3 U F F E R TO MODULE-1 AND RETURN T O
                              REMOTE.
                           V      C
    05:29:00 B A T C M D E R I F Y O R R E C T                                           T    D
                                                           COMMAND T R A N S M I T I M E I S P L A Y E D         ON
                              FORMAT 301.
                                     I
    05:30:00 NATCMD S E N DD L E - Z / A C T I V E                 ON
    0 5 : 3 5 : @ 0 NAT/DSS   CONB'IBM T H I R D COMMAND T R A N S M I S S I O N
                                       A T
    0 5 : 3 ? : 0 0 NATCMD A F T E R L L H R E                                             B    T
                                                            ( 3 ) COMMANDS H A V E E E N R A N S M I T T E D
                                   C                 ,         TI                     O
                              A N D O N F I R M E DR E T U R N OD L E - l / A C T I V E F F .
    05:41:51 DSS-43           HIGH ATE HANNEL
                                    R     C                      O N ( 1 K ) DUAL S U B C A R R I E R SSA
                              THRESHOLD        SHOULD          BE S E T T
                                                                        A         0.0 DB.

MORE


                                                         E-3
JrL005A
RR ANBE
      JOCC   JZED           OUTGOING MESSAGE
DE JJPL 005A
02/0001z
PAGE THREE
    06:04:0@ DSS-43     COMMAND MOD OFF
    05:54:00 DSS-43     TRAKSMITTER OFF
    06:14:53 DSS-43     LOS S/C-26
7 . TELEMETRY I D R REQUIREMENTS  (NOCC)
                O
           A . L W RATE ENGINEERING
               DOY-248/05:14:222    TO DOY 248:@6:15:002
           B . H.IGH RATE SCIENCE
               DOY-248:05:41:002    TO 248:06:15:002
8 . I F THERE ARE A N Y QUESTIONSCALL    J. NASH X-4491 OR R . E. NEVAREZ
    X-7163 REGARDS, REN .
     F
END O MESSAGE
02/01052 SEP 82 JJPL




                                  E-4
             APPENDIX F


RECOVERY
       STRATEGY   LOG FOR VIKING LANDER 1


    NovemberThroughFebruary   1983




                  F- 1
     The c h r o n o l o g y o f e v e n t s t h a t f o l l o w e d t h e s p a c e c r a f t e m e r g e n c y d e c l a r e d o n
        20,
November 1982,   and                 t h es u b s e q u e n te f f o r t st or e c o v e rt h es p a c e c r a f ts i g n a l
aregivenbelow:

November 19:DOY 324:SOL 2252: DSS 43:
     No d o w n l i n k o b t a i n e d d u r i n g t h i s r e g u l a r d o w n l i n k p a s s .

November 20:DOY 325:SOL 2253:
     Spacecraftemergencydeclared           by t h e V i k i n g P r o j e c t a t        0000 h o u r s b e c a u s e o f
     failuretoreceive   a s c h e d u l e dd o w n l i n kt r a n s m i s s i o nf r o m          .
                                                                                            V L 1 The o p e n i n g
     ofanundervoltageswitchonthelanderelectricalequipmentbuss                                            was
     suspected.

November 23:DOY 325:SOL 2256: DSS 43:
     T r a n s m i t uplink o n l y t o L a n d e r .                 The commands were t o i n c r e a s e b a t t e r y -
     c h a r g i n gf r e q u e n c y ,c l o s et h eu n d e r v o l t . a g es w i t c h ,a n dc a u s e  a d o w n l i n kt o
     o c c u r o n DOY 331.

November 26:DOY 331:SOL 2253: DSS 43:
     W h i l e t r a n s m i t t i n g commands t o i n i t i a t e t h e d o w n l i n k , t h e                 DSS 43 antenna
     h a l t e d due t o a h y d r a u l i cc o o l a n tl e a k ;t h ep a s s                   was c a n c e l e d .P r o j e c td i s -
     c o v e r e dt h a tt h el a n d e ra n t e n n ap o i n t i n gp a r a m e t e r s               i n t h el a n d e rc o m p u t e r
     memory h a d i n a d v e r t e n t l y b e e n o v e r w r i t t e n w i t h t h e b a t t e r y - c h a r g i n g              param-
     eters.          A new s t r a t e g y t h a t r e c o g n i z e s t h e l a n d e r a n t e n n a a s b e i n g o f f p o i n t
         lhli
     wa v e t o b e d e v e l o p e d f o r a l l f u t u r e                     uplink t r a n s m i s s i o n s .

December 02:DOY 336:SOL 2264: DSS 63:
     T r a n s m i t commands f o r a d o w n l i n k on DOY’ 338 w i t h VL-1 antenna i n a p a r k e d
     position.

December 04:DOY 338:SOL 2266: DSS 63:
     No d o w n l i n k o b s e r v e d d u r i n g t h i s p a s s .

December 06:DOY 340:SOL 2268: DSS 63:
     T r a n s m i t commands f o r d o w n l i n k o n                 DOY 3 4 1 with VL-1 antenna i n a p a r k e d
     position.

December 07:DOY 341:SOL 2269: DSS 63:
     Further set of  commands f o r a d o w n l i n k o n                              DOY 343 w i t h antenna i n p a r k e d
     position.

December 09:DOY 343:SOL 2271:
     Ops t e a m d i s c o v e r s t h a t 2 5 6 - b i t i d l e  sequence was i n a d v e r t e n t l y o m i t t e d f r o m
     t h eu n t i m e d commands s e n to n                       2266,
                                                          SOL 2264,       and 2268, t h u s i n v a l i d a t i n g
     t h o s e uplink sequences.

December 11:DOY 345:SOL 2273: DSS 1 4
     Command t r a n s m i s s i o n s f r o m DSS 14 now i n c l u d e d t h e c o r r e c t 2 5 6 - b i t i d l e                        se-
     quence.      This sequence                   was t o move t h e V L - 1 a n t e n n at o a known f a v o r a b l e
     E a r t h - p o i n tp o s i t i o n ,f o r       a d o w n l i n k on SOL 2274.            The          attempt t o r e p o s i t i o n
     thehigh-gainantenna                         was o n l y p a r t i a l l y s u c c e s s f u l b e c a u s e t h e h i g h - p o w e r
     t r a n s m i t t e rf a i l e ds e v e r a lt i m e sd u r i n gt h i s              pass.   However,               36 commands o f
     t h e p l a n n e d 60were s u c c e s s f u l l y t r a n s m i t t e d .


                                                                       F- 2
December 12:DOY 346:SOL: 2274: DSS 14:
     T h i s was i n t e n d e dt ob e         adownlink-onlypass.However,the                               commands t o
     initiatethedownlinkflagwerenottransmittedbecauseanoperationsprob-
     lempreventedtheproperidle                             sequence b e i n g e x e c u t e d b e f o r e t h e  command
     window     closed     a t 20042.   The              failuretoinitiatethe                 command sequence       cor-
     r e c t l y was s u b s e q u e n t l y i n v e s t i g a t e d , but noconclusiveproblemcouldbe
     found       .
December 17:DOY 351:SOL 2279: DSS 63:
     Commands w e r e t r a n s m i t t e d t o p a r k t h e a n t e n n a a n d i n i t i a t e              ad o w n l i n k      on
     SOL 2282.

December 20:DOY 355:SOL 2282: DSS 1 4 :
     Searched f o r a d o w n l i n k a f t e r t r a n s m i t t i n g t h e d o w n l i n k f l a g ,             b u t n o down-
     link d e t e c t e d .

December 23:DOW 358:SOL 2285: DSS 1 4 :
     T h i s uplink sequence was t o p a r k t h e a n t e n n a a n d c a u s e         adownlinktooccur
     o n SOL 2289.         A p p r o x i m a t e l y2 / 3o ft h i sp a s s     was conducted w i t h t h et r a n s -
     m i t t e r on r i g h t c i r c u l a r p o l a r i z a t i o n   (RCP) and1/3on   left circular polari-
     z a t i o n (LCP).

December 27:DOY 362:SOL 2289: DSS 43:
     Searched f o r a d o w n l i n k a f t e r t r a n s m i t t i n g t h e d o w n l i n k f l a g ,             b u t n o down-
     link d e t e c t e d .

December 31:DOY 365:SOL 2 2 9 2 : DSS 43:
     U p l i n k commands t o p a r k t h e a n t e n n a . F i r s t p a r t o f t h i s p a s s                 i n RCP, second
     p a r t i n l i n e a r p o l a r i z a t i o n a t t h e 45-degand90-degphase                            positions, w i t h
     t r a n s m i t t e r a t 80 k W .

January 04:DOY 004:SOL 2296: DSS 43?63:
     T h i s was a s p l i t pass w i t h DSS 43 t r a n s m i t t i n g t h e uplink t u r n - o n commands.
     The second p a r t o f t h e p a s s              w i t h DSS 63 i n i t i a t e d a d o w n l i n k s e a r c h with
     t h e S S I a n do p e n - l o o pr e c o r d i n g ,b u tn od o w n l i n kc o u l db ed e t e c t e d .

January05,1983
     P r o j e c t announcedsuspension o f f u r t h e r DSN s u p p o r t p e n d i n g a n i n - d e p t h
     investigationintothelanderantennapointingprogram.

F e b r u a r y 1:DOY 003:SOL 2324: DSS 43:
         The p a s so v e r DSS 43 onFebruary 1 was s a t i s f a c t o r y , w i t h 23 o f t h e p l a n n e d
         25-command sequences b e i n gt r a n s m i t t e d .                   The h i g h - p o w e rt r a n s m i t t e rt r i p p e d
         o f ff o u rt i m e sc a u s i n gt h el o s t        sequences.             The a u t o m a t i c command f a c i l i t y
         w o r k e dp e r f e c t l y .    Any one o f t h e commands w o u l d h a v e b e e n s u f f i c i e n t t o
         r e p r o g r a mt h e VL.        The 1 1 - h o u rp a s sa l l o w e df o raf u l l - E a r t hp a s sa sv i e w e d
         from Mars.

F e b r u a r y 03:DOY 035:SOL 2326: DSS 43:
         T h i s was thesecond o f t h e a u t o m a t i c D / L t r a n s m i s s i o n s f o l l o w i n g a n                  8-week
         U/L  absence.     (Assumed by t h el a c k o f r e s p o n s eo ft h es p a c e c r a f t . )                            No s i g -
         n a l was seenonthe     S S I by DSS 43.



                                                                  F- 3
    February 06:DOY 036/37:SOL               2328:           DSS 43:
         T h i sp a s sc o n s i s t e do f        a continuous command t o c l o s e t h e UV s w i t c h and p a r k
         theantenna.             (It w completedover
                                            l be
                                             li                                                         1
                                                                                   DSS 6 3 on February 1 ) TX power was
                W
         80 k , and t h e new a u t o m a t i c CMD S/W was used. Commands wereseparated by
         40 m i n t o e n s u r et h a tt h es p a c e c r a f tc o u l de x e c u t e         one command b e f o r e r e -
         c e i v i n gt h en e x t      a n db e f o r e . p r o c e s s i n gt h en e x t .  312 commands weresent.
         Therewerenotransmittertrips.

    February 10:DOY'41:SOL        2332:  DSS 63:
         T h i s was theremainder       o f t h e CMD sequence s e n tF e b r u a r y 6.     Because t h e
         DCO d i d n o t s t a r t ontime,the      first block of   commands      was    m i s s e d ;o t h e r w i s e
         a l l commands weresentok.

    February 11:DOY 42:SOL            2333:     DSS 63:
         The sequence c o n s i s t e d o f a TX sweep f o l l o w e d b y a n i d l e                sequenceand s h o r t
         s e t o f commands t oa c t i v a t et h ed o w n l i n k .      Even i f t h es p a c e c r a f th a dn o t
         r e c e i v e d any o f t h e commands i n t h e p a s t , a n a u t o m a t i c d o w n l i n k s h o u l d h a v e
         o c c u r r e da tt h i sp o i n t .    None was found.        A two-way sweep was t h e n made and
         a searchforthedownlinkusingthespectrumsignalindicator                                                 andopenloop
         r e c e i v e r s . No d o w n l i n k was found.

    February 16:DOY 047:SOL           2338:       DSS 63:
         Followinganuplinkacquisition                          sweep, a 25-command sequence was s e n t t o
I                   he             af d o                 ro
         change ts p a c e c r r a tcio n f i g u r a t ifo n m                                       tc
                                                                                  TWTAl/I4OD-EXCl and a o t i -
~                                                                   s    f h ed  n
         v a t e a d o w n l i n k . However, an i n t e n s i v e a r ca i l ftio d              a downlink
i        signal.

    February 18:DOY 49:SOL 2340: DSS 63:
         A 1 o n g . s e r i e s o f commands t o move t h e a n t e n n a t o                     i t s limit a n d t h e n p a r k a t
         E a r t h p o i n t were now s e n t f r o m D S S 63.                     T h i s shouldhaveenabledtheantenna
         and  computer            d r i v e t o come i n t o r e g i s t r a t i o n a t t h e           limit p o i n t .          I had
                                                                                                                                     t   been
         t h o u g h t t h a t some kind o f s t i c k i n g and f r i c t i o n may havecausedtheantenna
         and  computer            d r i v et ol o s ea l i g n m e n t .S i n c et h ea n t e n n ap o i n t i n gd i r e c t i o n
         was n o t known, commands w e r es e n tt h r o u g ht h ew h o l ev i e wp e r i o d                                    (10 h). O n
         t h en e x ta v a i l a b l ep a s s ,a ni m m e d i a t ed o w n l i n k              w i l l be initiated.

    February 25:DOY 56:SOL 2347: DSS14:
         A s h o r t u p l i n k - a c q u i s i t i o n sequence f o l l o w e d by a s e a r c h f o r t h e d o w n l i n k
         failed to find             a signal.            The R F I van a t Goldstone was a l s o u s e d t o s e a r c h
         f o r t h e d o w n l i n k w i t h i t s spectrum analyzer at a minimum d e t e c t i o n l e v e l o f
         -186 dBm. No s i g n a l was d e t e c t e d .




                                                                      F- 4
      APPENDIX G


ANNOTATED BIBLIOGRAPHY




        G1
      The e n t r i e s b e l o w may be ordered from the Superintendent of                                           Documents, U.S.
 Government P r i n t i n g O f f i c e , Washington, D.C., 20402.


 Images o f Mars (1980,                       32 pp.)

          NASA SP-444, Stock NO. 033-000-00793-1
          A c o l l e c t i o n o f 39 o f t h e b e s t o r b i t e r p h o t o g r a p h s f r o m t h e V i k i n g E x t e n d e d
          Mission, 1 9 7 7 t o 1979, w i t h d e s c r i p t i v e t e s t .

Mars:         The V i k i n gD i s c o v e r i e s      (1977,     32 pp.)

          NASA EP-146, Stock NO. 033-000-00703-5
          A nontechnical accountofthe findings of the first few                                               months o f t h e V i k i n g
          M i s s i o n w i t h 28 p i c t u r e s , i n c l u d i n g 7 i.n c o l o r .

                                 160
The M a r t i a n Landscape (1978,                          pp.)

          NASA SP-425, Stock NO. 33-000-00716-7
          A largebookcontainingover                      200 Viking Lander photographs                              i n c o l o r and
          b l a c k and w h i t e ,i n c l u d i n g   19stereopai.rs.Includes                          a f i r s t - p e r s o na c c o u n t
          of the preparations for                   and a c t u a l p h o t o g r a p h i n g o f M a r s f r o m         i t s surface.

V i k i n g - M a r sE x h i b i t     Package(1977)

         Stock NO. 033-000-00711-6
         A setofposters,including                         one 76.2 b y 101.6 cm, two 6 1 by 89 cm, and many
         s m a l l e r ones.     I n a d d i t i o nt op i c t u r e s ,m o s t l y          i n c o l o r ,t h e r ea r ed e s c r i p -
         t i o n s o f each s c i e n t i f i c i n s t r u m e n t o n t h e o r b i t e r s       and l a n d e r s and some o f
         t h e r e s u l t s o f eachexperiment.

VikingOrbiter                             (1980,
                             Views o f Mars    182                      pp.)

         NASA SP-441, Stock NO. 033-000-00795-7
         The v a r i o u s t y p e s o f g e o l o g i c f e a t u r e s o n      Mars a r e d e s c r i b e d and i l l u s t r a t e d
         b y some o f t h e b e s t o r b i t e r p i c t u r e s f r o m t h e f i r s t y e a r o f t h e V i k i n g m i s -
         sion; more t h a n 200 i l l u s t r a t i o n s .

V i k i n gP i c t u r e so fM a r s :S e t             No. 1 (1977)

         Stock NO. 033-000-00691-8
         A set of four color   and f i v e black-and-whitereproductions,              30.5 b y 63.5 cm,
         o f Marstaken by t h e cameras o n t h e V i k i n g O r b i t e r s and Landers.

V i k i n g 1 E a r l yR e s u l t s          (1976,    67 pp.)

         NASA SP-408, Stock NO. 033-000-00675-6
         The V i k i n g P r o j e c t , t h e o r b i t i n g and 1a.nding spacecraft, and t h e r e s u l t s
         obtained i n t h e f i r s t few weeks a t Mars are described               w i t h photographs,
         graphs, and diagrams.




                                                                      G- 2
         The e n t r i e s b e l o w may b e o r d e r e d f r o m t h e N a t i o n a l T e c h n i c a l I n f o r m a t i o n
S e r v i c e ,S p r i n g f i e l d ,V i r g i n i a , 22151.

The Mosaics o f Marsas                  Seen b y t h e V i k i n g L a n d e r        Cameras (1980,             75 pp.)

        Stock NO. N80-32311
        T h i sp u b l i c a t i o nd e s c r i b e st h e1 0p a n o r a m i cm o s a i c s            and v a r i o u s o t h e r image
        productsthatwerederivedby                               computer p r o c e s s i n g f r o m t h e i n d i v i d u a l p i c -
        t u r e so b t a i n e d by t h eV i k i n gL a n d e r s .            20 i l l u s t r a t i o n s .

Viking Lander Imaging Investigation During Extended                   and C o n t i n u a t i o n A u t o m a t i c
                          :
Missions, Volume 1 Lander 1 P i c t u r eC a t a l o go fE x p e r i m e n tD a t aR e c o r d            (1981,
650 pp. A v a i l a b l e soon)

        The format i s t h e same as t h a to ft h ep r i m a r ym i s s i o nc a t a l o g ,b e l o w . t
                                                                                                         I
        detailstheoperationoftheLander                   1 cameras from December 1976 t o February
        1979. Volume 2 onLander 2 w i l l b e i s s u e d l a t e r .

Viking Lander Imaging Investigation Picture Catalog of Primary Mission Experiment
DataRecord (1978, 560 pp.)

        Stock NO.      78N-20042
        A technicalencyclopediaoftheperformanceofthe                                      cameras o n t h e two V i k i n g
        L a n d e r sd u r i n gt h ef i r s tf o u r    months o ft h em i s s i o n .I n c l u d e d    i s a repro-
        ductionofeveryphotograph(smallsize                            and mediocre i n q u a l i t y ) a l o n g w i t h
        c o m p l e t ei n f o r m a t i o na b o u t where, when, and how each p i c t u r e was taken.




                                                                     G- 3
               \




 APPENDIX H


VIKING FACTS




      H- 1
iking              Event                                                                      1                                    Viking 2

                   Launch                                                        Aug. 20,
                                                                                 Sept.            1975                 1975                9,

                   Arrival                                           1976 June 19,                                                 Aug.   7, 1976

                   Landing                                                       July 20,
                                                                                 Sept.            1976                                     3,     1976

                   Site                           Planitia                      pia
                                                                           U t oChryse P l a n i t i a

                   Coordinates                  225.8"                    22.3"N,
                                                                     47.7"N,                   48.0"

                   O r b i t e r i n o r b i tdays 718.8 days1,509.9

                    ace
                    on
             s u r fL a n d e r                                                        1,316.1
                                                                                        days
                                                                                        days
                                                                                 2,100(4/20/82

                   End l a n d e r o p e r a t i o n s                           ( p r e d i c t e d ) 1994)                                  1
                                                                                                                                   A p r i l 1 , 1980
                                                                             .
                                                                             (   &JQL"         a a ,   l%%L-
                   End o ob ie e a t i o n s
                         r p trr                                                 Aug.    7,    1980                                J u l y 2 5 , 1978

                   Orbiter                                                                                     51,539

e       photos     Lander                                                                                                4,500

                   Photocoverage                                                 97% o f p l a n e t with r e s o l u t i o n o f 300 m
                                                                                 (1,000 f t ) o r b e t t e r .

                                                                                 25% o f p l a n e t w i t h r e s o l u t i o n     o f 25 m
                                                                                 (82 f t ) o r b e t t e r .

                   L a n d e rw e a t h e rr e p o r t s :m o r et h a n                 1m i l l i o n

                   O r b i t e ri n f r a r e do b s e r v a t i o n s :            more t h a n 1 m i l l i o n

                         w
                   Orbiter eight:                   2,325       kg

                            w          : k
                  L a n d e r e i g h t5 7 1 g

                  O r b i t e r s b u i l t by J e t P r o p u l s i o n L a b o r a t o r y

                  Lander b u i l t by M a r t i n M a r i e t t a A e r o s p a c e




                                                                                        H- 2                                              NASA-JPL--Coml..   L.A.. CslS

								
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